RNA binding protein and binding site useful for expression of recombinant molecules

ABSTRACT

The present invention relates to a gene expression system in eukaryotic and prokaryotic cells, preferably plant cells and intact plants. In particular, the invention relates to an expression system having a RB47 binding site upstream of a translation initiation site for regulation of translation mediated by binding of RB47 protein, a member of the poly(A) binding protein family. Regulation is further effected by RB60, a protein disulfide isomerase. The expression system is capable of functioning in the nuclear/cytoplasm of cells and in the chloroplast of plants. Translation regulation of a desired molecule is enhanced approximately 100 fold over that obtained without RB47 binding site activation.

This invention was made with government support under Contract No. GM 54659 by the National Institutes of Health and Contract No. DO-FG03-93ER20116 by the U.S. Department of Energy. The government has certain rights in the invention.

This is a stage application filed under 35 USC 371, of PCT/US98/00840, filed Jan. 16, 1998. This application claims benefit of provisional No. 60/035,955 filed Jan. 17, 1997 and provisional appln No. 60/069,400 filed Dec. 12, 1997.

TECHNICAL FIELD

The invention relates to expression systems and methods for expression of desired genes and gene products in cells. Particularly, the invention relates to a gene encoding a RNA binding protein useful for regulating gene expression in cells, the protein binding site, a gene encoding a regulating protein disulfide isomerase and methods and systems for gene expression of recombinant molecules.

BACKGROUND

Expression systems for expression of exogenous foreign genes in eukaryotic and prokaryotic cells are basic components of recombinant DNA technology. Despite the abundance of expression systems and their wide-spread use, they all have characteristic disadvantages. For example, while expression in E. coli is probably the most popular as it is easy to grow and is well understood, eukaryotic proteins expressed therein are not properly modified. Moreover, those proteins tend to precipitate into insoluble aggregates and are difficult to obtain in large amounts. Mammalian expression systems, while practical on small-scale protein production, are more difficult, time-consuming and expensive than in E. coli.

A number of plant expression systems exist as well as summarized in U.S. Pat. No. 5,234,834, the disclosures of which are hereby incorporated by reference. One advantage of plants or algae in an expression system is that they can be used to produce pharmacologically important proteins and enzymes on a large scale and in relatively pure form. In addition, micro-algae have several unique characteristics that make them ideal organisms for the production of proteins on a large scale. First, unlike most systems presently used to produce transgenic proteins, algae can be grown in minimal media (inorganic salts) using sunlight as the energy source. These algae can be grown in contained fermentation vessels or on large scale in monitored ponds. Ponds of up to several acres are routinely used for the production of micro-algae. Second, plants and algae have two distinct compartments, the cytoplasm and the chloroplast, in which proteins can be expressed. The cytoplasm of algae is similar to that of other eukaryotic organisms used for protein expression, like yeast and insect cell cultures. The chloroplast is unique to plants and algae and proteins expressed in this environment are likely to have properties different from those of cytoplasmically expressed proteins.

The present invention describes an expression system in which exogenous molecules are readily expressed in either prokaryotic or eukaryotic hosts and in either the cytoplasm or chloroplast. These beneficial attributes are based on the discovery and cloning of components of translation regulation in plants as described in the present invention.

Protein translation plays a key role in the regulation of gene expression across the spectrum of organisms (Kozak, Ann. Rev. Cell Biol., 8:197-225 (1992) and de Smit and Van Duin, Prog. Nucleic Acid Res. Mol. Biol., 38:1-35 (1990)). The majority of regulatory schemes characterized to date involve translational repression often involving proteins binding to mRNA to limit ribosome association (Winter et al., Proc. Natl. Acad. Sci., USA, 84:7822-7826 (1987) and Tang and Draper, Biochem., 29:4434-4439 (1990)). Translational activation has also been observed (Wulczyn and Kahmann, Cell, 65:259-269 (1991)), but few of the underlying molecular mechanisms for this type of regulation have been identified. In plants, light activates the expression of many genes. Light has been shown to activate expression of specific chloroplast encoded mRNAs by increasing translation initiation (Mayfield et al., Ann. Rev. Plant Physiol. Plant Mol. Biol., 46:147-166 (1995) and Yohn et al., Mol. Cell Biol., 16:3560-3566 (1996)). Genetic evidence in higher plants and algae has shown that nuclear encoded factors are required for translational activation of specific chloroplast encoded mRNAs (Rochaix et al., Embo J., 8:1013-1021 (1989), Kuchka et al., Cell, 58:869-876 (1989), Girard-Bascou et al., Embo J., 13:3170-3181 (1994), Kim et al., Plant Mol. Biol., 127:1537-1545 (1994).

In the green algae Chlamydomonas reinhardtii, a number of nuclear mutants have been identified that affect translation of single specific mRNAs in the chloroplast, often acting at translation initiation (Yohn et al., supra, (1996)). Mutational analysis of chloroplast mRNAs has identified sequence elements within the 5' untranslated region (UTR) of mRNAs that are required for translational activation (Mayfield et al., supra, (1995), Mayfield et al., J. Cell Biol., 127:1537-1545 (1994) and Rochaix, Ann. Rev. Cell Biol., 8:1-28 (1992)), and the 5' UTR of a chloroplast mRNA can confer a specific translation phenotype on a reporter gene in vivo (Zerges and Rochaix, Mol. Cell Biol., 14:5268-5277 (1994) and Staub and Maliga, Embo J., 12:601-606 (1993).

Putative translational activator proteins were identified by purifying a complex of four proteins that binds with high affinity and specificity to the 5' UTR of the chloroplast encoded psbA mRNA [encoding the D1 protein, a major component of Photosystem II (PS II)] (Danon and Mayfield, Embo J., 10:3993-4001 (1991)). Binding of these proteins to the 5' UTR of psbA mRNA correlates with translation of this mRNA under a variety of physiological (Danon and Mayfield, id., (1991)) and biochemical conditions (Danon and Mayfield, Science, 266:1717-1719 (1994) and Danon and Mayfield, Embo J., 13:2227-2235 (1994)), and in different genetic backgrounds (Yohn et al., supra, (1996)). The binding of this complex to the psbA mRNA can be regulated in vitro in response to both redox potential (Danon and Mayfield, Science, 266:1717-1719 (1994)) and phosphorylation (Danon and Mayfield, Embo J., 13:2227-2235 (1994)), both of which are thought to transduce the light signal to activate translation of psbA mRNA. The 47 kDa member of the psbA RNA binding complex (RB47) is in close contact with the RNA, and antisera specific to this protein inhibits binding to the psbA mRNA in vitro (Danon and Mayfield, supra, (1991)).

Although the translational control of psbA mRNA by RB47 has been reported, the protein has not been extensively characterized and the gene encoding RB47 has not been identified, cloned and sequenced. In addition, the regulatory control of the activation of RNA binding activity to the binding site by nuclear-encoded trans-acting factors, such as RB60, have not been fully understood. The present invention now describes the cloning and sequencing of both RB47 and RB60. Based on the translation regulation mechanisms of RB47 and RB60 with the RB47 binding site, the present invention also describes a translation regulated expression system for use in both prokaryotes and eukaryotes.

BRIEF DESCRIPTION OF THE INVENTION

The RB47 gene encoding the RB47 activator protein has now been cloned and sequenced, and the target binding site for RB47 on messenger RNA (mRNA) has now been identified. In addition, a regulatory protein disulfide isomerase, a 60 kilodalton protein referred to as RB60, has also been cloned, sequenced and characterized. Thus, the present invention is directed to gene expression systems in eukaryotic and prokaryotic cells based on translational regulation by RB47 protein, its binding site and the RB60 regulation of RB47 binding site activation.

More particularly, the present invention describes the use of the RB47 binding site, i.e., a 5' untranslated region (UTR) of the chloroplast psbA gene, in the context of an expression system for regulating the expression of genes encoding a desired recombinant molecule. Protein translation is effected by the combination of the RB47 binding site and the RB47 binding protein in the presence of protein translation components. Regulation can be further imposed with the use of the RB60 regulatory protein disulfide isomerase. Therefore, the present invention describes reagents and expression cassettes for controlling gene expression by affecting translation of a coding nucleic acid sequence in a cell expression system.

Thus, in one embodiment, the invention contemplates a RB47 binding site sequence, i.e., a mRNA sequence, typically a mRNA leader sequence, which contains the RB47 binding site. A preferred RB47 binding site is psbA mRNA. For use in expressing recombinant molecules, the RB47 binding site is typically inserted 5' to the coding region of the preselected molecule to be expressed. In a preferred embodiment, the RB47 binding site is inserted into the 5' untranslated region along with an upstream psbA promoter to drive the expression of a preselected nucleic acid encoding a desired molecule. In alternative embodiments, the RB47 binding site is inserted into the regulatory region downstream of any suitable promoter present in a eukaryotic or prokaryotic expression vector. Preferably, the RB47 binding site is positioned within 100 nucleotides of the translation initiation site. In a further aspect, 3' to the coding region is a 3' untranslated region (3' UTR) necessary for transcription termination and RNA processing.

Thus, in a preferred embodiment, the invention contemplates an expression cassette or vector that contains a transcription unit constructed for expression of a preselected nucleic acid or gene such that upon transcription, the resulting mRNA contains the RB47 binding site for regulation of the translation of the preselected gene transcript through the binding of the activating RB47 protein. The RB47 protein is provided endogenously in a recipient cell and/or is a recombinant protein expressed in that cell.

Thus, the invention also contemplates a nucleic acid molecule containing the sequence of the RB47 gene. The nucleic acid molecule is preferably in an expression vector capable of expressing the gene in a cell for use in interacting with a RB47 binding site. The invention therefore contemplates an expressed recombinant RB47 protein. In one embodiment, the RB47 binding site and RB47 encoding nucleotide sequences are provided on the same genetic element. In alternative embodiments, the RB47 binding site and RB47 encoding nucleotide sequences are provided separately.

The invention further contemplates a nucleic acid molecule containing the sequence encoding the 69 kilodalton precursor to RB47. In alternative embodiments, the RB47 nucleic acid sequence contains a sequence of nucleotides to encode a histidine tag. Thus, the invention relates to the use of recombinant RB47, precursor RB47, and histidine-modified RB47 for use in enhancing translation of a desired nucleic acid.

The invention further contemplates a nucleic acid molecule containing a nucleotide sequence of a polypeptide which regulates the binding of RB47 to RB47 binding site. A preferred regulatory molecule is the protein disulfide isomerase RB60. The RB60-encoding nucleic acid molecule is preferably in an expression vector capable of expressing the gene in a cell for use in regulating the interaction of RB47 with a RB47 binding site. Thus, the invention also contemplates an expressed recombinant RB60 protein. In one embodiment, the RB47 binding site, RB47 encoding and RB60 encoding nucleotide sequences are provided on the same genetic element. In alternative embodiments, the expression control nucleotide sequences are provided separately. In a further aspect, the RB60 gene and RB47 binding site sequence are provided on the same construct.

The invention can therefore be a cell culture system, an in vitro expression system or a whole tissue, preferably a plant, in which the transcription unit is present that contains the RB47 binding site and further includes a (1) transcription unit capable of expressing RB47 protein or (2) the endogenous RB47 protein itself for the purpose of enhancing translation of the preselected gene having an RB47 binding site in the mRNA. Preferred cell culture systems are eukaryotic and prokaryotic cells. Particularly preferred cell culture systems include plants and more preferably algae.

A further preferred embodiment includes (1) a separate transcription unit capable of expressing a regulatory molecule, preferably RB60 protein, or (2) the endogenous RB60 protein itself for the purpose of regulating translation of the preselected gene having an RB47 binding site in the mRNA. In an alternative preferred embodiment, one transcription unit is capable of expressing both the RB47 and RB60 proteins. In a further aspect, the RB47 binding site sequence and RB60 sequence are provided on the same construct.

In one aspect of the present invention, plant cells endogenously containing RB47 and RB60 proteins are used for the expression of recombinant molecules, such as proteins or polypeptides, through activation of the RB47 binding in an exogenously supplied expression cassette. Alternatively, stable plant cell lines containing endogenous RB47 and RB60 are first generated in which RB47 and/or RB60 proteins are overexpressed. Overexpression is obtained preferably through the stable transformation of the plant cell with one or more expression cassettes for encoding recombinant RB47 and RB60. In a further embodiment, stable cell lines, such as mammalian or bacterial cell lines, lacking endogenous RB47 and/or RB60 proteins are created that express exogenous RB47 and/or RB60.

Plants for use with the present invention can be a transgenic plant, or a plant in which the genetic elements of the invention have been introduced. Based on the property of controlled translation provided by the combined use of the RB47 protein and the RB47 binding site, translation can be regulated for any gene product, and the system can be introduced into any plant species. Similarly, the invention is useful for any prokaryotic or eukaryotic cell system.

Methods for the preparation of expression vectors is well known in the recombinant DNA arts, and for expression in plants is well known in the transgenic plant arts. These particulars are not essential to the practice of the invention, and therefore will not be considered as limiting.

The invention allows for high level of protein synthesis in plant chloroplasts and in the cytoplasm of both prokaryotic and eukaryotic cells. Because the chloroplast is such a productive plant organ, synthesis in chloroplasts is a preferred site of translation by virtue of the large amounts of protein that can be produced. This aspect provides for great advantages in agricultural production of mass quantities of a preselected protein product.

The invention further provides for the ability to screen for agonists or antagonists of the binding of RB47 to the RB47 binding site using the expression systems as described herein. Antagonists of the binding are useful in the prevention of plant propagation.

Also contemplated by the present invention is a screening assay for agonists or antagonists of RB60 in a manner analogous to that described above for RB47. Such agonists or antagonists would be useful in general to modify expression of RB60 as a way to regulate cellular processes in a redox manner.

Kits containing expression cassettes and expression systems, along with packaging materials comprising a label with instructions for use, as described in the claimed embodiments are also contemplated for use in practicing the methods of this invention.

Other uses will be apparent to one skilled in the art in light of the present disclosures.

BRIEF DESCRIPTION OF DRAWINGS

In the figures forming a portion of this disclosure:

FIGS. 1A-1D show the complete protein amino acid residue sequence of RB47 is shown from residues 1-623, together with the corresponding nucleic acid sequence encoding the RB47 sequence, from base 1 to base 2732. The nucleotide coding region is shown from base 197-2065, the precursor form. The mature form is from nucleotide position 197-1402. Also shown is the mRNA leader, bases 1-196, and poly A tail of the mRNA, bases 2066-2732. Both the nucleotide and amino acid sequence are listed in SEQ ID NO 5.

FIGS. 2A-2B show the complete protein amino acid residue sequence of RB60 is shown from residues 1-488, together with the corresponding nucleic acid sequence from base 1 to base 2413, of which bases 16-1614 encode the RB60 sequence. Both the nucleotide and amino acid sequence are listed in SEQ ID NO 10.

FIGS. 3A-3C show the complete sequence of the psbA mRNA, showing both encoded psbA protein amino acid residue sequence (residues 1-352) and the nucleic acid sequence as further described in Example 3 is illustrated. Both the nucleotide and amino acid sequence are listed in SEQ ID NO 13.

FIG. 4 is a schematic diagram of an expression cassette containing on one transcription unit from 5' to 3', a promoter region derived from the psbA gene for encoding the D1 protein from C. reinhardtii further containing a transcription initiation site (TS), the RB47 binding site, a region for insertion of a foreign or heterologous coding region, a RB47 coding region, a RB60 coding region, and the 3' flanking region containing transcription termination site (TS), flanked by an origin of replication and selection marker. Restriction endonuclease sites for facilitating insertion of the independent genetic elements are indicated and further described in Example 4A.

FIGS. 5A-5B show the nucleotide and amino acid sequence of the RB47 molecule containing a histidine tag, the sequences of which are also listed in SEQ ID NO 14.

FIG. 6 is a schematic diagram of an expression cassette containing on one transcription unit from 5' to 3', a promoter region derived from the psbA gene for encoding the D1 protein from C. reinhardtii further containing a transcription initiation site (TS), the RB47 binding site, a region for RB47 is also shown in FIGS. 1A-1D (SEQ ID NO 5). As described in Section 2 above, the predicted protein sequence from the cloned cDNA contained both the derived peptide sequences of RB47 and is highly homologous to poly(A) binding proteins (PABP) from a variety of eukaryotic organisms.

2. CLONING OF RB60

To clone the cDNA encoding the 60 kDa psbA mRNA binding protein (RB60), the psbA-specific RNA binding proteins were purified from light-grown C. reinhardtii cells using heparin-agarose chromatography followed by psbA RNA affinity chromatography (RAC). RAC-purified proteins were separated by two-dimensional polyacrylamide gel electrophoresis. The region corresponding to RB60 was isolated from the PVDF membrane. RB60 protein was then digested with trypsin. Unambiguous amino acid sequences were obtained from two peptide tryptic fragments (WFVDGELASDYNGPR (SEQ ID NO 6) and (QLILWTTADDLKADAEIMTVFR (SEQ ID NO 7)) as described above for RB47. The calculated molecular weights of the two tryptic peptides used for further analysis precisely matched with the molecular weights determine by mass spectrometry. The DNA sequence corresponding to one peptide of 22 amino acid residues was amplified by PCR using degenerate oligonucleotides, the forward primer 5'CGCGGATCCGAYGCBGAGATYATGAC3' (SEQ ID NO 8) and the reverse primer 5'CGCGAATTCGTCATRATCTCVGCRTC3' (SEQ ID NO 9), where R can be A or G (the other IUPAC nucleotides have been previously defined above). The amplified sequence was then used to screen a λ-gt10 cDNA library from C. reinhardtii. Three clones were identified with the largest being 2.2 kb. Selection and sequencing was performed as described for RB47 cDNA.

The resulting RB60 cDNA sequence is available via GenBank (Accession Number AF027727). The nucleotide and encoded amino acid sequence of RB60 is also shown in FIGS. 2A-2B (SEQ ID NO 10). The protein coding sequence of 488 amino acid residues corresponds to nucleotide positions 16-1614 of the 2413 base pair sequence. The predicted amino acid sequence of the cloned cDNA contained the complete amino acid sequences of the two tryptic peptides. The amino acid sequence of the encoded protein revealed that it has high sequence homology to both plant and mammalian protein disulfide isomerase (PDI), and contains the highly conserved thioredoxin-like domains with --CysGlyHisCys-- (--CGHC--) (SEQ ID NO 11) catalytic sites in both the N-terminal and C-terminal regions and the --LysAspGluLeu-- (--KDEL--) (SEQ ID NO 12) endoplasmic reticulum (ER) retention signal at the C-terminus found in all PDIs. PDI is a mutifunctional protein possessing enzymatic activities for the formation, reduction, and isomerization of disulfide bonds during protein folding, and is typically found in the ER. The first 30 amino acid residues of RB60 were found to lack sequence homology with the N-terminal signal sequence of PDI from plants or mammalian cells. However, this region has characteristics of chloroplast transit peptides of C. reinhardtii, which have similarities with both mitochondrial and higher plant chloroplast presequences. A transit peptide sequence should override the function of the --KDEL-- ER retention signal and target the protein to the chloroplast since the --KDEL-- signal acts only to retain the transported protein in the ER.

3. Preparation of psbA Promoter Sequence and RB47 Binding Site Nucleotide Sequence

The chloroplast psbA gene from the green unicellular alga C. reinhardii was cloned and sequenced as described by Erickson et al., Embo J., 3:2753-2762 (1984), the disclosure of which is hereby incorporated by reference. The DNA sequence of the coding regions and the 5' and 3' untranslated (UTR) flanking sequences of the C. reinhardii psbA gene is shown in FIGS. 3A-3C. The psbA gene sequence is also available through GenBank as further discussed in Example 4. The nucleotide sequence is also listed as SEQ ID NO 13. The deduced amino acid sequence (also listed in SEQ ID NO 13) of the coding region is shown below each codon beginning with the first methionine in the open reading frame. Indicated in the 5' non-coding sequence are a putative Shine-Dalgarno sequence in the dotted box, two putative transcription initiation sites determined by S1 mapping (S1) and the Pribnow-10 sequence in the closed box. Inverted repeats of eight or more base pairs are marked with arrows and labeled A-D. A direct repeat of 31 base pairs with only two mismatches is marked with arrows labeled 31. Indicated in the 3' non-coding sequence is a large inverted repeat marked by a forward arrow and the SI cleavage site marking the 3' end of the mRNA. Both the 5' and 3' untranslated regions are used in preparing one of the expression cassettes of this invention as further described below.

The 5' UTR as previously discussed contains both the psbA promoter and the RB47 binding site. The nucleotide sequence defining the psbA promoter contains the region of the psbA DNA involved in binding of RNA polymerase to initiate transcription. The -10 sequence component of the psbA promoter is indicated by the boxed nucleotide sequence upstream of the first S1 while the -35 sequence is located approximately 35 bases before the putative initiation site. As shown in FIGS. 3A-3C, the -10 sequence is boxed, above which is the nucleotide position (-100) from the first translated codon. The -35 sequence is determined accordingly. A psbA promoter for use in an expression cassette of this invention ends at the first indicated S1 site (nucleotide position -92 as counting from the first ATG) in FIGS. 3A-3C and extends to the 5' end (nucleotide position -251 as shown in FIGS. 3A-3C). Thus, the promoter region is 160 bases in length. A more preferred promoter region extends at least 100 nucleotides to the 5' end from the S1 site. A most preferred region contains nucleotide sequence ending at the s1 site and extending 5' to include the -35 sequence, i.e., from -92 to -130 as counted from the first encoded amino acid residue (39 bases).

The psbA RB47 binding site region begins at the first S1 site as shown in FIGS. 3A-3C and extends to the first adenine base of the first encoded methionine residue. Thus, a psbA RB47 binding site in the psbA gene corresponds to the nucleotide positions from -91 to -1 as shown in FIG. 3A-3C.

The above-identified regions are used to prepare expression constructs as described below. The promoter and RB47 binding site regions can be used separately; for example, the RB47 binding site sequence can be isolated and used in a eukaryotic or prokaryotic plasmid with a non-psbA promoter. Alternatively, the entire psbA 5' UTR having 251 nucleotides as shown in FIGS. 3A-3C is used for the regulatory region in an expression cassette containing both the psbA promoter and RB47 binding site sequence as described below.

4. Preparation of Expression Vectors and Expression of Coding Sequences

A. Constructs Containing an psbA Promoter, an RB47 Binding Site Nucleotide Sequence, a Desired Heterologous Coding Sequence, an RB47-Encoding Sequence and an RB60-Encoding Sequence

Plasmid expression vector constructs, alternatively called plasmids, vectors, constructs and the like, are constructed containing various combinations of elements of the present invention as described in the following examples. Variations of the positioning and operably linking of the genetic elements described in the present invention and in the examples below are contemplated for use in practicing the methods of this invention. Methods for manipulating DNA elements into operable expression cassettes are well known in the art of molecular biology. Accordingly, variations of control elements, such as constitutive or inducible promoters, with respect to prokaryotic or eukaryotic expression systems as described in Section C. are contemplated herein although not enumerated. Moreover, the expression the various elements is not limited to one transcript producing one mRNA; the invention contemplates protein expression from more than one transcript if desired.

As such, while the examples below recite one or two types of expression cassettes, the genetic elements of RB47 binding site, any desired coding sequence, in combination with RB47 and RB60 coding sequences along with a promoter are readily combined in a number of operably linked permeations depending on the requirements of the cell system selected for the expression. For example, for expression in a chloroplast, endogenous RB47 protein is present therefore an expression cassette having an RB47 binding site and a desired coding sequence is minimally required along with an operative promoter sequence. Overexpression of RB47 may be preferable to enhance the translation of the coding sequence; in that case, the chloroplast is further transformed with an expression cassette containing an RB47-encoding sequence. Although the examples herein and below utilize primarily the sequence encoding the precursor form of RB47, any of the RB47-encoding sequences described in the present invention, i.e., RB47 precursor, mature RB47 and histidine-modified RB47 are contemplated for use in any expression cassette and system as described herein. To regulate the activation of translation, an RB60-encoding element is provided to the expression system to provide the ability to regulate redox potential in the cell as taught in Section B. These examples herein and below represent a few of the possible permutations of genetic elements for expression in the methods of this invention.

In one embodiment, a plasmid is constructed containing an RB47 binding site directly upstream of an inserted coding region for a heterologous protein of interest, and the RB47 and RB60 coding regions. Heterologous refers to the nature of the coding region being dissimilar and not from the same gene as the regulatory molecules in the plasmid, such as RB47 and RB60. Thus, all the genetic elements of the present invention are produced in one transcript from the IPTG-inducible psbA promoter. Alternative promoters are similarly acceptable.

The final construct described herein for use in a prokaryotic expression system makes a single mRNA from which all three proteins are translated. The starting plasmid is any E. coli based plasmid containing an origin of replication and selectable marker gene. For this example, the Bluescript plasmid, pBS, commercially available through Stratagene, Inc., La Jolla, Calif., which contains a polylinker-cloning site and an ampicilin resistant marker is selected for the vector.

The wild-type or native psbA gene (Erickson et al., Embo J., 3:2753-2762 (1984), also shown in FIGS. 3A-3C, is cloned into pBS at the EcoRI and BamHI sites of the polylinker. The nucleotide sequence of the psbA gene is available on GenBank with the 5' UTR and 3' UTR respectively listed in Accession Numbers X01424 and X02350. The EcoRI site of psbA is 1.5 kb upstream of the psbA initiation codon and the BamHI site is 2 kb downstream of the stop codon. This plasmid is referred to as pDl.

Using site-directed PCR mutagenesis, well known to one of ordinary skill in the art, an NdeI site is placed at the initiation codon of psbA in the pDl plasmid so that the ATG of the NdeI restriction site is the ATG initiation codon. This plasmid is referred to as pDl/Nde. An Nde site is then placed at the initiation codon of the gene encoding the heterologous protein of interest and an Xho I site is placed directly downstream (within 10 nucleotides) of the TAA stop codon of the heterologous protein coding sequence. Again using site-directed mutagenesis, an XhoI site is placed within 10 nucleotides of the initiation codon of RB47, the preparation of which is described in Example 2, and an NotI site is placed directly downstream of the stop codon of RB47. The heterologous coding region and the RB47 gene are then ligated into pDl/Nde so that the heterologous protein gene is directly adjacent to the RB47 binding site and the RB47 coding region is downstream of the heterologous coding region, using the Xho I site at the heterologous stop codon and the Not I site of the pDl polylinker.

These genetic manipulations result in a plasmid containing the 5' end of the psbA gene including the promoter region and with the RB47 binding site immediately upstream of a heterologous coding region, and the RB47 coding region immediately downstream of the heterologous coding region. The nucleotides between the stop codon of the heterologous coding region and the initiation codon of the RB47 coding region is preferably less than 20 nucleotides and preferably does not contain any additional stop codons in any reading frame. This plasmid is referred to as pD1/RB47.

Using site-directed mutagenesis, a NotI site is placed immediately (within 10 nucleotides) upstream of the initiation codon of RB60, the preparation of which is described in Example 2, and an Xba I site is placed downstream of the RB60 stop codon. This DNA fragment is then ligated to the 3' end of the psbA gene using the Xba I site found in the 3' end of the psbA gene so that the psbA 3' end is downstream of the RB60 coding region. This fragment is then ligated into the pD1/RB47 plasmid using the NotI and BamHI sites so that the RB60 coding region directly follows the RB47 coding region. The resulting plasmid is designated pD1/RB47/RB60. Preferably there is less then 20 nucleotides between the RB47 and RB60 coding regions and preferably there are no stop codons in any reading frame in that region. The final plasmid thus contains the following genetic elements operably linked in the 5' to 3' direction: the 5' end of the psbA gene with a promoter capable of directing transcription in chloroplasts, an RB47 binding site, a desired heterologous coding region, the RB47 coding region, the RB60 coding region, and the 3' end of the psbA gene which contains a transcription termination and mRNA processing site, and an E. coli origin of replication and amplicillin resistance gene. A diagram of this plasmid with the restriction sites is shown in FIG. 4.

Expression of pD1/RB47/RB60 in E. coli to produce recombinant RB47, RB60 and the recombinant heterologous protein is performed as described in Example 4B. The heterologous protein is then purified as further described.

Expression cassettes in which the sequences encoding RB47 and RB60 are similarly operably linked to a heterologous coding sequence having the psbA RB47 binding site as described in Example 3 are prepared with a different promoter for use in eukaryotic, such as mammalian expression systems. In this aspect, the cassette is similarly prepared as described above with the exception that restriction cloning sites are dependent upon the available multiple cloning sites in the recipient vector. Thus, the RB47 binding site prepared in Example 3 is prepared for directed ligation into a selected expression vector downstream of the promoter in that vector. The RB47 and RB60 coding sequences are obtained from the pD1/RB47/RB60 plasmid by digestion with XhoI and XbaI and inserted into a similarly digested vector if the sites are present. Alternatively, site-directed mutagenesis is utilized to create appropriate linkers. A desired heterologous coding sequence is similarly ligated into the vector for expression.

B. Constructs Containing RB47 Nucleotide Sequence

1) Purified Recombinant RB47 Protein

In one approach to obtain purified recombinant RB47 protein, the full length RB47 cDNA prepared above was cloned into the E. coli expression vector pET3A (Studier et al., Methods Enzymol., 185:60-89 (1990)), also commercially available by Novagen, Inc., Madison, Wis. and transformed into BL21 E. coli cells. The cells were grown to a density of 0.4 (OD₆₀₀), then induced with 0.5 mM IPTG. Cells were then allowed to grow for an additional 4 hours, at which point they were pelleted and frozen.

Confirmation of the identity of the cloned cDNA as encoding the authentic RB47 protein was accomplished by examining protein expressed from the cDNA by immunoblot analysis and by RNA binding activity assay. The recombinant RB47 protein produced when the RB47 cDNA was expressed was recognized by antisera raised against the C. reinhardtii RB47 protein. The E. coli expressed protein migrated at 80 kDa on SDS-PAGE, but the protein was actually 69 kDa, as determined by mass spectrometry of the E. coli expressed protein. This mass agrees with the mass predicted from the cDNA sequence. A 60 kDa product was also produced in E. coli, and recognized by the antisera against the C. reinhardtii protein, which is most likely a degradation or early termination product of the RB47 cDNA. The recombinant RB47 protein expressed from the RB47 cDNA is recognized by the antisera raised against the C. reinhardtii protein at levels similar to the recognition of the authentic C. reinhardtii RB47 protein, demonstrating that the cloned cDNA produces a protein product that is immunologically related to the naturally produced RB47 protein. In order to generate a recombinant equivalent of the endogenous native RB47, the location of the 47 kDa polypeptide was mapped on the full-length recombinant protein by comparing mass spectrometric data of tryptic digests of the C. reinhardtii 47 kDa protein and the full-length recombinant protein. Thus, peptide mapping by mass spectrometry has shown that the endogenous RB47 protein corresponds primarily to the RNA binding domains contained within the N-terminal region of the predicted precursor protein, suggesting that a cleavage event is necessary to produce the mature 47 kDa protein. Thus, full-length recombinant RB47 is 69 kDa and contains a carboxy domain that is cleaved in vivo to generate the endogenous mature form of RB47 that is 47 kDa.

To determine if the heterologously expressed RB47 protein was capable of binding the psbA RNA, the E. coli expressed protein was purified by heparin agarose chromatography. The recombinant RB47 protein expressed in E. coli was purified using a protocol similar to that used previously for purification of RB47 from C. reinhardtii. Approximately 5 g of E. coli cells grown as described above were resuspended in low salt extraction buffer (10 mM Tris [pH 7.5], 10 mM NaCl, 10 mM MgCl₂, 5 mM β-mercaptoethanol) and disrupted by sonication. The soluble cell extract was applied to a 5 mL Econo-Pac heparin cartridge (Bio-Rad) which was washed prior to elution of the RB47 protein (Danon and Mayfield, Embo J., 10:3993-4001 (1991)).

The E. coli expressed protein that bound to the heparin agarose matrix was eluted from the column at the same salt concentration as used to elute the authentic C. reinhardtii RB47 protein. This protein fraction was used in in vitro binding assays with the psbA 5' UTR. Both the 69 and 60 kDa E. coli expressed proteins crosslinked to the radiolabeled psbA 5' UTR at levels similar to crosslinking of the endogenous RB47 protein, when the RNA/protein complex is subjected to UV irradiation.

Heparin agarose purified proteins, both from the E. coli expressed RB47 cDNA and from C. reinhardtii cells, were used in an RNA gel mobility shift assay to determine the relative affinity and specificity of these proteins for the 5' UTR of the psbA mRNA. The E. coli expressed proteins bound to the psbA 5' UTR in vitro with properties that are similar to those of the endogenous RB47 protein purified from C. reinhardtii. RNA binding to both the E. coli expressed and the endogenous RB47 protein was competed using either 200 fold excess of unlabeled psbA RNA or 200 fold excess of poly(A) RNA. RNA binding to either of these proteins was poorly competed using 200 fold excess of total RNA or 200 fold excess of the 5' UTR of the psbD or psbC RNAs. Different forms of the RB47 protein (47 kDa endogenous protein vs. the 69 kDa E. coli expressed protein) may account for the slight differences in mobility observed when comparing the binding profiles of purified C. reinhardtii protein to heterologously expressed RB47.

The mature form of RB47 is also produced in recombinant form by the insertion by PCR of an artificial stop codon in the RB47 cDNA at nucleotide positions 1403-1405 with a stop codon resulting in a mature RB47 recombinant protein having 402 amino acids as shown in FIGS. 1A-1D. An example of this is shown in FIGS. 5A-5B for the production of a recombinant histidine-modified RB47 mature protein as described below. The complete RB47 cDNA is inserted into an expression vector, such as pET3A as described above, for expression of the mature 47 kDa form of the RB47 protein. In the absence of the inserted stop codon, the transcript reads through to nucleotide position 2066-2068 at the TAA stop codon to produce the precursor RB47 having the above-described molecular weight characteristics and 623 amino acid residues.

Recombinant RB47 is also expressed and purified in plant cells. For this aspect, C. reinhardtii strains were grown in complete media (Tris-acetate-phosphate [TAP] (Harris, The Chlamydonas Sourcebook, San Diego, Calif., Academic Press (1989)) to a density of 5×10⁶ cells/mL under constant light. Cells were harvested by centrifugation at 4° C. for 5 minutes at 4,000 g. Cells were either used immediately or frozen in liquid N₂ for storage at -70° C.

Recombinant RB47 protein was also produced as a modified RB47 protein with a histidine tag at the amino-terminus according to well known expression methods using pET19-D vectors available from Novagen, Inc., Madison, Wis. The nucleotide and amino acid sequence of a recombinant histidine-modified RB47 of the mature 47 kDa form is shown in FIGS. 5A-5B with the nucleotide and amino acid sequence also listed in SEQ ID NO 14. Thus the nucleotide sequence of a histidine-modified RB47 is 1269 bases in length. The precursor form of the RB47 protein is similarly obtained in the expression system, both of which are modified by the presence of a histidine tag that allows for purification by metal affinity chromatography.

The recombinant histidine-modified RB47 purified through addition of a poly-histidine tag followed by Ni⁺² column chromatography showed similar binding characteristics as that described for recombinant precursor RB47 described above.

C. Constructs Containing RB60 Nucleotide Sequence

In one approach to obtain purified recombinant RB60 protein, the full-length RB60 cDNA prepared above was cloned into the E. coli expression vector pET3A (Studier et al., Methods Enzymol., 185:60-89 (1990)), also commercially available by Novagen, Inc., Madison, Wis. and transformed into BL21 E. coli cells. The cells were grown to a density of 0.4 (OD₆₀₀), then induced with 0.5 mM IPTG. Cells were then allowed to grow for an additional 4 hours, at which point they were pelleted and frozen.

Recombinant histidine-modified RB60 was also expressed with a pET19-D vector as described above for RB47 that was similarly modified. Purification of the recombinant RB60 proteins was performed as described for RB47 thereby producing recombinant RB60 proteins for use in the present invention.

The RB60 coding sequence is also mutagenized for directional ligation into an selected vector for expression in alternative systems, such as mammalian expression systems.

D. Constructs Containing an RB47-Encoding Sequence and an RB60-Encoding Sequence

To prepare an expression cassette for encoding both RB47 and RB60, one approach is to digest plasmid pD1/RB47/RB60 prepared above with XhoI and XbaI to isolate the fragment for both encoding sequences. The fragment is then inserted into a similarly digested expression vector if available or is further mutagenized to prepare appropriate restriction sites.

Alternatively, the nucleotide sequences of RB47 and RB60, as described in Example 2, are separately prepared for directional ligation into a selected vector.

An additional embodiment of the present invention is to prepare an expression cassette containing the RB47 binding site along with the coding sequences for RB47 and RB60, the plasmid pD1/RB47/RB60 prepared above is digested with NdeI and XhoI to prepare an expression cassette in which any desired coding sequence having similarly restriction sites is directionally ligated. Expression vectors containing both the RB47 and RB60 encoding sequences in which the RB47 binding site sequence is utilized with a different promoter are also prepared as described in Example 4A.

E. Constructs Containing an RB47 Binding Site Nucleotide Sequence, Insertion Sites for a Desired Heterologous Coding Sequence, and an RB47-Encoding Sequence

In another permutation, a plasmid or expression cassette is constructed containing an RB47 binding site directly upstream of an inserted coding region for a heterologous protein of interest, and the RB47 coding region. The final construct described herein for use in a prokaryotic expression system makes a single mRNA from which both proteins are translated.

The plasmid referred to as pD1/RB47 is prepared as described above in Example 4A. A diagram of this plasmid with the restriction sites is shown in FIG. 6.

Expression of pD1/RB47 in E. coli to produce recombinant RB47 and the recombinant heterologous protein is performed as described in above. The heterologous protein is then purified as further described.

To produce an expression cassette that allows for insertion of an alternative desired coding sequence, the plasmid pD1/RB47 is digested with NdeI and XhoI resulting in a vector having restriction endonuclease sites for insertion of a desired coding sequence operably linked to a RB47 binding site and RB47 coding sequence on one transcriptional unit.

F. Constructs Containing an RB47 Binding Site Nucleotide Sequence, Insertion Sites for a Desired Heterologous Coding Sequence, and an RB47-Encoding Sequence

In another permutation, a plasmid or expression cassette is constructed containing an RB47 binding site directly upstream of an inserted coding region for a heterologous protein of interest, and the RB60 coding region. The final construct described herein for use in a prokaryotic expression system makes a single mRNA from which both proteins are translated. In this embodiment, a separate construct encoding recombinant RB47 as described in Example 4B is co-transformed into the E. coli host cell for expression.

The plasmid referred to as pD1/RB60 is prepared as described above for pD1/RB47 in Example 4A with the exception that XhoI and XbaI sites are created on RB60 rather than RB47.

Expression of pD1/RB60 in E. coli to produce recombinant RB60 and the recombinant heterologous protein is performed as described in above with the combined expression of RB47 from a separate expression cassette. The heterologous protein is then purified as further described.

To produce an expression cassette that allows for insertion of an alternative desired coding sequence, the plasmid pD1/RB60 is digested with NdeI and XhoI resulting in a vector having restriction endonuclease sites for insertion of a desired coding sequence operably linked to a RB47 binding site and RB60 coding sequence on one transcriptional unit.

G. Constructs Containing RB47 Binding Site Nucleotide Sequence and Heterologous Coding Sequences

1) Expression of Recombinant Tetanus Toxin Single Chain Antibody

The examples herein describe constructs that are variations of those described above. The constructs described below contain an RB47 binding site sequence and a heterologous coding sequence. The activating protein RB47 was endogenously provided in the chloroplast and or plant cell. In other aspects however as taught by the methods of the present invention, the chloroplast is further transformed with an RB47-expression construct as described above for overexpression of RB47 to enhance translation capacities.

A strain of the green algae Chlamydomonas reinhardtii was designed to allow expression of a single chain antibody gene in the chloroplast. The transgenically expressed antibody was produced from a chimeric gene containing the promoter and 5' untranslated region (UTR) of the chloroplast psbA gene prepared as described above, followed by the coding region of a single chain antibody (encoding a tetanus toxin binding antibody), and then the 3' UTR of the psbA gene also prepared as described above to provide for transcription termination and RNA processing signals. This construct is essentially pD1/Nde including a heterologous coding sequence having a 3' XbaI restriction site for ligation with the 3' psbA gene and is diagramed in FIG. 7.

The psbA-single chain construct was first transformed into C. reinhardtii chloroplast and transformants were then screened for single chain gene integration. Transformation of chloroplast was performed via bolistic delivery as described in U.S. Pat. Nos. 5,545,818 and 5,553,878, the disclosures of which are hereby incorporated by reference. Transformation is accomplished by homologous recombination via the 5' and 3' UTR of the psbA mRNA.

As shown in FIG. 8, two of the transformants that contained the single chain chimeric gene produced single chain antibodies at approximately 1% of total protein levels. The transgenic antibodies were of the correct size and were completely soluble, as would be expected of a correctly folded protein. Few degradation products were detectable by this Western analysis, suggesting that the proteins were fairly stable within the chloroplast. To identify if the produced antibody retained the binding capacity for tetanus toxin, ELISA assays were performed using a mouse-produced Fab, from the original tetanus toxin antibody, as the control. The chloroplast single chain antibody bound tetanus toxin at levels similar to Fab, indicating that the single chain antibody produced in C. reinhardtii is a fully functional antibody. These results clearly demonstrate the ability of the chloroplast to synthesis and accumulate function antibody molecules resulting from the translational activation of an RB47 binding site in an expression cassette by endogenous RB47 protein in the chloroplast.

2) Expression of Bacterial Luciferase Enzyme Having Two Subunits

For the production of molecules that contain more than one subunit, such as dIgA and bacterial luciferase enzyme, several proteins must be produced in stoichiometric quantities within the chloroplast. Chloroplast have an advantage for this type of production over cytoplasmic protein synthesis in that translation of multiple proteins can originate from a single mRNA. For example, a dicistronic mRNA having 5' and 3' NdeI and XbaI restriction sites and containing both the A and B chains of the bacterial luciferase enzyme was inserted downstream of the psbA promoter and 5' UTR of the pD1/Nde construct prepared in Example 4A above. In this construct, the bacterial LuxAB coding region was ligated between the psbA 5' UTR and the psbA 3' end in an E. coli plasmid that was then transformed into Chlamydomonas reinhardtii cells as described above for expression in the chloroplast. A schematic of the construct is shown in FIG. 9. Single transformant colonies were then isolated. A plate containing a single isolate was grown for 10 days on complete media and a drop of the luciferase substrate n-Decyl Aldehyde was placed on the plate and the luciferase visualized by video-photography in a dark chamber. Both proteins were synthesized from this single mRNA and luciferase activity accumulated within the chloroplast as shown in FIG. 10. Some mRNA within plastids contained as many as 5 separate proteins encoded on a single mRNA.

3) Expression of Dimeric IgA

To generate dimeric IgA, the construct shown in FIG. 11 is engineered so that the psbA promoter and 5' UTR are used to drive the synthesis of the light chain and heavy chains of an antibody, and the J chain normally associated with IgA molecules. The nucleic acid sequences for the dimeric IgA are inserted into the RB47 binding site construct prepared in Example 4A. The construct is then transformed into C. reinhardtii cells as previously described for expression of the recombinant dIgA.

Production of these three proteins within the plastid allows for the self assembly of a dimeric IgA (dIgA). Production of this complex is monitored in several ways. First, Southern analysis of transgenic algae is used to identify strains containing the polycistronic chimeric dIgA gene. Strains positive for integration of the dIgA gene are screened by Northern analysis to ensure that the chimeric mRNA is accumulating. Western blot analysis using denaturing gels is used to monitor the accumulation of the individual light, heavy and J chain proteins, and native gels Western blot analysis will be used to monitor the accumulation of the assembled dIgA molecule.

By using a single polycistronic mRNA in the context of RB47 regulated translation, two of the potential pitfalls in the assembly of multimeric dIgA molecule are overcome. First, this construct ensures approximately stoichiometric synthesis of the subunits, as ribosomes reading through the first protein are likely to continue to read through the second and third proteins as well. Second, all of the subunits are synthesized in close physical proximity to each other, which increases the probability of the proteins self assembling into a multimeric molecule. Following the production of a strain producing dIgA molecules, the production of dIgA on an intermediate scale by growing algae in 300 liter fermentors is then performed. Larger production scales are then performed thereafter.

The foregoing specification, including the specific embodiments and examples, is intended to be illustrative of the present invention and is not to be taken as limiting. Numerous other variations and modifications can be effected without departing from the true spirit and scope of the invention.

    __________________________________________________________________________     #             SEQUENCE LISTING                                                   - -  - - <160> NUMBER OF SEQ ID NOS: 14                                        - - <210> SEQ ID NO 1                                                         <211> LENGTH: 15                                                               <212> TYPE: PRT                                                                <213> ORGANISM: Chlamydomonas reinhardtii                                       - - <400> SEQUENCE: 1                                                          - - Gln Tyr Gly Phe Val His Phe Glu Asp Gln Al - #a Ala Ala Asp Arg             1               5 - #                 10 - #                 15               - -  - - <210> SEQ ID NO 2                                                    <211> LENGTH: 14                                                               <212> TYPE: PRT                                                                <213> ORGANISM: Chlamydomonas reinhardtii                                       - - <400> SEQUENCE: 2                                                          - - Gly Phe Gly Phe Ile Asn Phe Lys Asp Ala Gl - #u Ser Ala Ala                 1               5 - #                 10                                      - -  - - <210> SEQ ID NO 3                                                    <211> LENGTH: 32                                                               <212> TYPE: DNA                                                                <213> ORGANISM: Artificial Sequence                                            <220> FEATURE:                                                                 <223> OTHER INFORMATION: Description of Artificial - #Sequence:                      oligonucleotide primer                                                    - - <400> SEQUENCE: 3                                                          - - cagtacggyt tcgtbcaytt cgaggaycag gc       - #                  - #               32                                                                       - -  - - <210> SEQ ID NO 4                                                    <211> LENGTH: 40                                                               <212> TYPE: DNA                                                                <213> ORGANISM: Artificial Sequence                                            <220> FEATURE:                                                                 <223> OTHER INFORMATION: Description of Artificial - #Sequence:                      oligonucleotide primer                                                    - - <400> SEQUENCE: 4                                                          - - ggaattcggy ttcggyttca tyaacttcaa ggaygcbgag     - #                       - #    40                                                                       - -  - - <210> SEQ ID NO 5                                                    <211> LENGTH: 2846                                                             <212> TYPE: DNA                                                                <213> ORGANISM: Chlamydomonas reinhardtii                                      <220> FEATURE:                                                                 <221> NAME/KEY: CDS                                                            <222> LOCATION: (197)..(2065)                                                   - - <400> SEQUENCE: 5                                                          - - gaattcgcgg ccgctccgtg gttggtcctc atggtgtctt tttgaagagg ac -              #ctgagcct     60                                                                  - - ttcacccaaa tatatcaaaa aacccgggca accggccaaa aaaattgcaa aa -             #gcctctcg    120                                                                  - - taggcacaaa agacctattc tagccatcaa ctttgtatcc gacgctgccg tt -             #tagctgcg    180                                                                  - - cgtcttgaag tcaagc atg gcg act act gag tcc tcg - #gcc ccg gcg gcc        acc    232                                                                                         - #Met Ala Thr Thr Glu Ser Ser Ala Pro Ala A - #la         Thr                                                                                                - #  1               5 - #                 10                - - acc cag ccg gcc agc acc ccg ctg gcg aac tc - #g tcg ctg tac gtc ggt           280                                                                        Thr Gln Pro Ala Ser Thr Pro Leu Ala Asn Se - #r Ser Leu Tyr Val Gly                     15         - #         20         - #         25                       - - gac ctg gag aag gat gtc acc gag gcc cag ct - #g ttc gag ctc ttc tcc           328                                                                        Asp Leu Glu Lys Asp Val Thr Glu Ala Gln Le - #u Phe Glu Leu Phe Ser                 30             - #     35             - #     40                           - - tcg gtt ggc cct gtg gcc tcc att cgc gtg tg - #c cgc gat gcc gtc acg           376                                                                        Ser Val Gly Pro Val Ala Ser Ile Arg Val Cy - #s Arg Asp Ala Val Thr             45                 - # 50                 - # 55                 - # 60        - - cgc cgc tcg ctg ggc tac gcc tac gtc aac ta - #c aac agc gct ctg gac           424                                                                        Arg Arg Ser Leu Gly Tyr Ala Tyr Val Asn Ty - #r Asn Ser Ala Leu Asp                             65 - #                 70 - #                 75               - - ccc cag gct gct gac cgc gcc atg gag acc ct - #g aac tac cat gtc gtg           472                                                                        Pro Gln Ala Ala Asp Arg Ala Met Glu Thr Le - #u Asn Tyr His Val Val                         80     - #             85     - #             90                   - - aac ggc aag cct atg cgc atc atg tgg tcg ca - #c cgc gac cct tcg gcc           520                                                                        Asn Gly Lys Pro Met Arg Ile Met Trp Ser Hi - #s Arg Asp Pro Ser Ala                     95         - #        100         - #        105                       - - cgc aag tcg ggc gtc ggc aac atc ttc atc aa - #g aac ctg gac aag acc           568                                                                        Arg Lys Ser Gly Val Gly Asn Ile Phe Ile Ly - #s Asn Leu Asp Lys Thr                110              - #   115              - #   120                           - - atc gac gcc aag gcc ctg cac gac acc ttc tc - #g gcc ttc ggc aag att           616                                                                        Ile Asp Ala Lys Ala Leu His Asp Thr Phe Se - #r Ala Phe Gly Lys Ile            125                 1 - #30                 1 - #35                 1 -       #40                                                                               - - ctg tcc tgc aag gtt gcc act gac gcc aac gg - #c gtg tcg aag ggc         tac      664                                                                     Leu Ser Cys Lys Val Ala Thr Asp Ala Asn Gl - #y Val Ser Lys Gly Tyr                           145  - #               150  - #               155               - - ggc ttc gtg cac ttc gag gac cag gcc gct gc - #c gat cgc gcc att cag           712                                                                        Gly Phe Val His Phe Glu Asp Gln Ala Ala Al - #a Asp Arg Ala Ile Gln                        160      - #           165      - #           170                   - - acc gtc aac cag aag aag att gag ggc aag at - #c gtg tac gtg gcc ccc           760                                                                        Thr Val Asn Gln Lys Lys Ile Glu Gly Lys Il - #e Val Tyr Val Ala Pro                    175          - #       180          - #       185                       - - ttc cag aag cgc gct gac cgc ccc agg gca ag - #g acg ttg tac acc aac           808                                                                        Phe Gln Lys Arg Ala Asp Arg Pro Arg Ala Ar - #g Thr Leu Tyr Thr Asn                190              - #   195              - #   200                           - - gtg ttc gtc aag aac ttg ccg gcc gac atc gg - #c gac gac gag ctg ggc           856                                                                        Val Phe Val Lys Asn Leu Pro Ala Asp Ile Gl - #y Asp Asp Glu Leu Gly            205                 2 - #10                 2 - #15                 2 -       #20                                                                               - - aag atg gcc acc gag cac ggc gag atc acc ag - #c gcg gtg gtc atg         aag      904                                                                     Lys Met Ala Thr Glu His Gly Glu Ile Thr Se - #r Ala Val Val Met Lys                           225  - #               230  - #               235               - - gac gac aag ggc ggc agc aag ggc ttc ggc tt - #c atc aac ttc aag gac           952                                                                        Asp Asp Lys Gly Gly Ser Lys Gly Phe Gly Ph - #e Ile Asn Phe Lys Asp                        240      - #           245      - #           250                   - - gcc gag tcg gcg gcc aag tgc gtg gag tac ct - #g aac gag cgc gag atg          1000                                                                        Ala Glu Ser Ala Ala Lys Cys Val Glu Tyr Le - #u Asn Glu Arg Glu Met                    255          - #       260          - #       265                       - - agc ggc aag acc ctg tac gcc ggc cgc gcc ca - #g aag aag acc gag cgc          1048                                                                        Ser Gly Lys Thr Leu Tyr Ala Gly Arg Ala Gl - #n Lys Lys Thr Glu Arg                270              - #   275              - #   280                           - - gag gcg atg ctg cgc cag aag gcc gag gag ag - #c aag cag gag cgt tac          1096                                                                        Glu Ala Met Leu Arg Gln Lys Ala Glu Glu Se - #r Lys Gln Glu Arg Tyr            285                 2 - #90                 2 - #95                 3 -       #00                                                                               - - ctg aag tac cag agc atg aac ctg tac gtc aa - #g aac ctg tcc gac         gag     1144                                                                     Leu Lys Tyr Gln Ser Met Asn Leu Tyr Val Ly - #s Asn Leu Ser Asp Glu                           305  - #               310  - #               315               - - gag gtc gac gac gac gcc ctg cgt gag ctg tt - #c gcc aac tct ggc acc          1192                                                                        Glu Val Asp Asp Asp Ala Leu Arg Glu Leu Ph - #e Ala Asn Ser Gly Thr                        320      - #           325      - #           330                   - - atc acc tcg tgc aag gtc atg aag gac ggc ag - #c ggc aag tcc aag ggc          1240                                                                        Ile Thr Ser Cys Lys Val Met Lys Asp Gly Se - #r Gly Lys Ser Lys Gly                    335          - #       340          - #       345                       - - ttc ggc ttc gtg tgc ttc acc agc cac gac ga - #g gcc acc cgg ccg ccc          1288                                                                        Phe Gly Phe Val Cys Phe Thr Ser His Asp Gl - #u Ala Thr Arg Pro Pro                350              - #   355              - #   360                           - - gtg acc gag atg aac ggc aag atg gtc aag gg - #c aag ccc ctg tac gtg          1336                                                                        Val Thr Glu Met Asn Gly Lys Met Val Lys Gl - #y Lys Pro Leu Tyr Val            365                 3 - #70                 3 - #75                 3 -       #80                                                                               - - gcc ctg gcg cag cgc aag gac gtg cgc cgt gc - #c acc cag ctg gag         gcc     1384                                                                     Ala Leu Ala Gln Arg Lys Asp Val Arg Arg Al - #a Thr Gln Leu Glu Ala                           385  - #               390  - #               395               - - aac atg cag gcg cgc atg ggc atg ggc gcc at - #g agc cgc ccg ccg aac          1432                                                                        Asn Met Gln Ala Arg Met Gly Met Gly Ala Me - #t Ser Arg Pro Pro Asn                        400      - #           405      - #           410                   - - ccg atg gcc ggc atg agc ccc tac ccc ggc gc - #c atg ccg ttc ttc gct          1480                                                                        Pro Met Ala Gly Met Ser Pro Tyr Pro Gly Al - #a Met Pro Phe Phe Ala                    415          - #       420          - #       425                       - - ccc ggc ccc ggc ggc atg gct gct ggc ccg cg - #c gct ccg ggc atg atg          1528                                                                        Pro Gly Pro Gly Gly Met Ala Ala Gly Pro Ar - #g Ala Pro Gly Met Met                430              - #   435              - #   440                           - - tac ccg ccc atg atg ccg ccg cgc ggc atg cc - #t ggc ccc ggc cgc ggc          1576                                                                        Tyr Pro Pro Met Met Pro Pro Arg Gly Met Pr - #o Gly Pro Gly Arg Gly            445                 4 - #50                 4 - #55                 4 -       #60                                                                               - - ccc cgc ggc ccc atg atg ccg ccc cag atg at - #g ggt ggc ccc atg         atg     1624                                                                     Pro Arg Gly Pro Met Met Pro Pro Gln Met Me - #t Gly Gly Pro Met Met                           465  - #               470  - #               475               - - ggc ccg ccc atg ggc ccc ggg cgc ggc cgt gg - #c ggc cgc ggc ccc tcc          1672                                                                        Gly Pro Pro Met Gly Pro Gly Arg Gly Arg Gl - #y Gly Arg Gly Pro Ser                        480      - #           485      - #           490                   - - ggc cgc ggc cag ggc cgc ggc aac aac gcc cc - #t gcc cag cag ccc aag          1720                                                                        Gly Arg Gly Gln Gly Arg Gly Asn Asn Ala Pr - #o Ala Gln Gln Pro Lys                    495          - #       500          - #       505                       - - ccc gcc gct gag ccg gcc gcc gcg ccc gcc gc - #c gcc gcc ccc gct gcc          1768                                                                        Pro Ala Ala Glu Pro Ala Ala Ala Pro Ala Al - #a Ala Ala Pro Ala Ala                510              - #   515              - #   520                           - - gcg gcg cct gcc gcc gcg gcg gag ccg gag gc - #c ccc gcc gcc cag cag          1816                                                                        Ala Ala Pro Ala Ala Ala Ala Glu Pro Glu Al - #a Pro Ala Ala Gln Gln            525                 5 - #30                 5 - #35                 5 -       #40                                                                               - - ccg ctg acc gcc tcc gcg ctg gcc gcc gcc gc - #g ccg gag cag cag         aag     1864                                                                     Pro Leu Thr Ala Ser Ala Leu Ala Ala Ala Al - #a Pro Glu Gln Gln Lys                           545  - #               550  - #               555               - - atg atg atc ggc gag cgc ctg tac ccg cag gt - #g gcg gag ctg cag ccc          1912                                                                        Met Met Ile Gly Glu Arg Leu Tyr Pro Gln Va - #l Ala Glu Leu Gln Pro                        560      - #           565      - #           570                   - - gac ctg gct ggc aag atc acc ggc atg ctg ct - #g gag atg gac aac gcc          1960                                                                        Asp Leu Ala Gly Lys Ile Thr Gly Met Leu Le - #u Glu Met Asp Asn Ala                    575          - #       580          - #       585                       - - gag ctt ctg atg ctt ctg gag tcg cac gag gc - #g ctg gtg tcc aag gtg          2008                                                                        Glu Leu Leu Met Leu Leu Glu Ser His Glu Al - #a Leu Val Ser Lys Val                590              - #   595              - #   600                           - - gac gag gcc atc gct gtg ctc aag cag cac aa - #c gtg att gcc gag gag          2056                                                                        Asp Glu Ala Ile Ala Val Leu Lys Gln His As - #n Val Ile Ala Glu Glu            605                 6 - #10                 6 - #15                 6 -       #20                                                                               - - aac aag gct taaagcgcct gcacgcttgt gcgggctggt ggcgccggc - #g                  2105                                                                       Asn Lys Ala                                                                     - -  - - cgcgccggcg ctgcttgggc cgccggcagc atgggcgcgg cggacgcggt gt -         #gggagcag   2165                                                                  - - tgcttgctgc ttctggccgc cgtgaagccg cgccgaactg gggcggacgg ca -             #ggctggcg   2225                                                                  - - ttgacgccgg cgcgccacaa cacaaagttg gtggcgtgaa agtctctggg cg -             #tgctccgg   2285                                                                  - - acggttgtaa ggttttaaga actggctttt ggccgggttg ccgcccaaag gc -             #ggaacggc   2345                                                                  - - ggtcttttca ggccaatcac atccggctgg aaaaattctt accaaagcca ac -             #ccctgcac   2405                                                                  - - ccaaaaattt cgggttccga aagaacactc cccttttttc cggcaacgcg tt -             #ctttcaag   2465                                                                  - - gccaatcact ttccgggttg gaagaaaatg ttacccggaa aaggcgggaa gc -             #cccctgca   2525                                                                  - - cccggacaag ttattcgggg tttcgccggg aatgagcaag cgttcgggct gt -             #tggccgta   2585                                                                  - - tcgcgaacgc tgtcggggtg tcaggcgcca gaaggaagga tgacgttttg gt -             #gaaggggt   2645                                                                  - - gcaaactgag cacacgagtt ttggcaatag acgtggagaa agtccagtgc gg -             #ggtgaggc   2705                                                                  - - ggatagcgga atcaagcgtg gcgggtccct ggcgagacga gacgcttctg tt -             #gttttgct   2765                                                                  - - gagccctttg atggcacaat cgcactgttt tgagcaggcg actgtaaagt gc -             #ccgacgct   2825                                                                  - - aaaaaagcgg ccgcgaattc c           - #                  - #                     2846                                                                      - -  - - <210> SEQ ID NO 6                                                    <211> LENGTH: 15                                                               <212> TYPE: PRT                                                                <213> ORGANISM: Chlamydomonas reinhardtii                                       - - <400> SEQUENCE: 6                                                          - - Trp Phe Val Asp Gly Glu Leu Ala Ser Asp Ty - #r Asn Gly Pro Arg             1               5 - #                 10 - #                 15               - -  - - <210> SEQ ID NO 7                                                    <211> LENGTH: 22                                                               <212> TYPE: PRT                                                                <213> ORGANISM: Chlamydomonas reinhardtii                                       - - <400> SEQUENCE: 7                                                          - - Gln Leu Ile Leu Trp Thr Thr Ala Asp Asp Le - #u Lys Ala Asp Ala Glu         1               5 - #                 10 - #                 15               - - Ile Met Thr Val Phe Arg                                                                20                                                                 - -  - - <210> SEQ ID NO 8                                                    <211> LENGTH: 26                                                               <212> TYPE: DNA                                                                <213> ORGANISM: Artificial Sequence                                            <220> FEATURE:                                                                 <223> OTHER INFORMATION: Description of Artificial - #Sequence:                      oligonucleotide primer                                                    - - <400> SEQUENCE: 8                                                          - - cgcggatccg aygcbgagat yatgac          - #                  - #                   26                                                                       - -  - - <210> SEQ ID NO 9                                                    <211> LENGTH: 26                                                               <212> TYPE: DNA                                                                <213> ORGANISM: Artificial Sequence                                            <220> FEATURE:                                                                 <223> OTHER INFORMATION: Description of Artificial - #Sequence:                      oligonucleotide primer                                                    - - <400> SEQUENCE: 9                                                          - - cgcgaattcg tcatratctc vgcrtc          - #                  - #                   26                                                                       - -  - - <210> SEQ ID NO 10                                                   <211> LENGTH: 2413                                                             <212> TYPE: DNA                                                                <213> ORGANISM: Chlamydomonas reinhardtii                                      <220> FEATURE:                                                                 <221> NAME/KEY: CDS                                                            <222> LOCATION: (16)..(1614)                                                    - - <400> SEQUENCE: 10                                                         - - gagtacgttt acgcc atg aac cgt tgg aac ctt ctt - #gcc ctt acc ctg ggg           51                                                                                          Met - #Asn Arg Trp Asn Leu Leu Ala Leu Thr Leu G - #ly                          - # 1               5  - #                10                  - - ctg ctg ctg gtg gca gcg ccc ttc acc aag ca - #c cag ttt gct cat gct            99                                                                        Leu Leu Leu Val Ala Ala Pro Phe Thr Lys Hi - #s Gln Phe Ala His Ala                     15         - #         20         - #         25                       - - tcc gat gag tat gag gac gac gag gag gac ga - #t gcc ccc gcc gcc cct           147                                                                        Ser Asp Glu Tyr Glu Asp Asp Glu Glu Asp As - #p Ala Pro Ala Ala Pro                 30             - #     35             - #     40                           - - aag gac gac gac gtc gac gtt act gtg gtg ac - #c gtc aag aac tgg gat           195                                                                        Lys Asp Asp Asp Val Asp Val Thr Val Val Th - #r Val Lys Asn Trp Asp             45                 - # 50                 - # 55                 - # 60        - - gag acc gtc aag aag tcc aag ttc gcg ctt gt - #g gag ttc tac gct cct           243                                                                        Glu Thr Val Lys Lys Ser Lys Phe Ala Leu Va - #l Glu Phe Tyr Ala Pro                             65 - #                 70 - #                 75               - - tgg tgc ggc cac tgc aag acc ctc aag cct ga - #g tac gct aag gct gcc           291                                                                        Trp Cys Gly His Cys Lys Thr Leu Lys Pro Gl - #u Tyr Ala Lys Ala Ala                         80     - #             85     - #             90                   - - acc gcc ctg aag gct gct gct ccc gat gcc ct - #t atc gcc aag gtc gac           339                                                                        Thr Ala Leu Lys Ala Ala Ala Pro Asp Ala Le - #u Ile Ala Lys Val Asp                     95         - #        100         - #        105                       - - gcc acc cag gag gag tcc ctg gcc cag aag tt - #c ggc gtg cag ggc tac           387                                                                        Ala Thr Gln Glu Glu Ser Leu Ala Gln Lys Ph - #e Gly Val Gln Gly Tyr                110              - #   115              - #   120                           - - ccc acc ctc aag tgg ttc gtt gat ggc gag ct - #g gct tct gac tac aac           435                                                                        Pro Thr Leu Lys Trp Phe Val Asp Gly Glu Le - #u Ala Ser Asp Tyr Asn            125                 1 - #30                 1 - #35                 1 -       #40                                                                               - - ggc ccc cgc gac gct gat ggc att gtt ggc tg - #g gtg aag aag aag         act      483                                                                     Gly Pro Arg Asp Ala Asp Gly Ile Val Gly Tr - #p Val Lys Lys Lys Thr                           145  - #               150  - #               155               - - ggc ccc ccc gcc gtg acc gtt gag gac gcc ga - #c aag ctg aag tcc ctg           531                                                                        Gly Pro Pro Ala Val Thr Val Glu Asp Ala As - #p Lys Leu Lys Ser Leu                        160      - #           165      - #           170                   - - gag gcg gac gct gag gtc gtt gtc gtc ggc ta - #c ttc aag gcc ctg gag           579                                                                        Glu Ala Asp Ala Glu Val Val Val Val Gly Ty - #r Phe Lys Ala Leu Glu                    175          - #       180          - #       185                       - - ggc gag atc tac gac acc ttc aag tcc tac gc - #c gcc aag acc gag gac           627                                                                        Gly Glu Ile Tyr Asp Thr Phe Lys Ser Tyr Al - #a Ala Lys Thr Glu Asp                190              - #   195              - #   200                           - - gtg gtg ttc gtg cag acc acc agc gcc gac gt - #c gcc aag gcc gcc ggc           675                                                                        Val Val Phe Val Gln Thr Thr Ser Ala Asp Va - #l Ala Lys Ala Ala Gly            205                 2 - #10                 2 - #15                 2 -       #20                                                                               - - ctg gac gcc gtg gac acc gtg tcc gtg gtc aa - #g aac ttc gcc ggt         gag      723                                                                     Leu Asp Ala Val Asp Thr Val Ser Val Val Ly - #s Asn Phe Ala Gly Glu                           225  - #               230  - #               235               - - gac cgc gcc acc gcc gtc ctg gcc acg gac at - #c gac act gac tcc ctg           771                                                                        Asp Arg Ala Thr Ala Val Leu Ala Thr Asp Il - #e Asp Thr Asp Ser Leu                        240      - #           245      - #           250                   - - acc gcg ttc gtc aag tcg gag aag atg ccc cc - #c acc att gag ttc aac           819                                                                        Thr Ala Phe Val Lys Ser Glu Lys Met Pro Pr - #o Thr Ile Glu Phe Asn                    255          - #       260          - #       265                       - - cag aag aac tct gac aag atc ttc aac agc gg - #c atc aac aag cag ctg           867                                                                        Gln Lys Asn Ser Asp Lys Ile Phe Asn Ser Gl - #y Ile Asn Lys Gln Leu                270              - #   275              - #   280                           - - att ctg tgg acc acc gcc gac gac ctg aag gc - #c gac gcc gag atc atg           915                                                                        Ile Leu Trp Thr Thr Ala Asp Asp Leu Lys Al - #a Asp Ala Glu Ile Met            285                 2 - #90                 2 - #95                 3 -       #00                                                                               - - act gtg ttc cgc gag gcc agc aag aag ttc aa - #g ggc cag ctg gtg         ttc      963                                                                     Thr Val Phe Arg Glu Ala Ser Lys Lys Phe Ly - #s Gly Gln Leu Val Phe                           305  - #               310  - #               315               - - gtg acc gtc aac aac gag ggc gac ggc gcc ga - #c ccc gtc acc aac ttc          1011                                                                        Val Thr Val Asn Asn Glu Gly Asp Gly Ala As - #p Pro Val Thr Asn Phe                        320      - #           325      - #           330                   - - ttc ggc ctc aag ggc gcc acc tcg cct gtg ct - #g ctg ggc ttc ttc atg          1059                                                                        Phe Gly Leu Lys Gly Ala Thr Ser Pro Val Le - #u Leu Gly Phe Phe Met                    335          - #       340          - #       345                       - - gag aag aac aag aag ttc cgc atg gag ggc ga - #g ttc acg gct gac aac          1107                                                                        Glu Lys Asn Lys Lys Phe Arg Met Glu Gly Gl - #u Phe Thr Ala Asp Asn                350              - #   355              - #   360                           - - gtg gct aag ttc gcc gag agc gtg gtg gac gg - #c acc gcg cag gcc gtg          1155                                                                        Val Ala Lys Phe Ala Glu Ser Val Val Asp Gl - #y Thr Ala Gln Ala Val            365                 3 - #70                 3 - #75                 3 -       #80                                                                               - - ctc aag tcg gag gcc atc ccc gag gac ccc ta - #t gag gat ggc gtc         tac     1203                                                                     Leu Lys Ser Glu Ala Ile Pro Glu Asp Pro Ty - #r Glu Asp Gly Val Tyr                           385  - #               390  - #               395               - - aag att gtg ggc aag acc gtg gag tct gtg gt - #t ctg gac gag acc aag          1251                                                                        Lys Ile Val Gly Lys Thr Val Glu Ser Val Va - #l Leu Asp Glu Thr Lys                        400      - #           405      - #           410                   - - gac gtg ctg ctg gag gtg tac gcc ccc tgg tg - #c ggc cac tgc aag aag          1299                                                                        Asp Val Leu Leu Glu Val Tyr Ala Pro Trp Cy - #s Gly His Cys Lys Lys                    415          - #       420          - #       425                       - - ctg gag ccc atc tac aag aag ctg gcc aag cg - #c ttt aag aag gtg gat          1347                                                                        Leu Glu Pro Ile Tyr Lys Lys Leu Ala Lys Ar - #g Phe Lys Lys Val Asp                430              - #   435              - #   440                           - - tcc gtc atc atc gcc aag atg gat ggc act ga - #g aac gag cac ccc gag          1395                                                                        Ser Val Ile Ile Ala Lys Met Asp Gly Thr Gl - #u Asn Glu His Pro Glu            445                 4 - #50                 4 - #55                 4 -       #60                                                                               - - atc gag gtc aag ggc ttc cct acc atc ctg tt - #c tat ccc gcc ggc         agc     1443                                                                     Ile Glu Val Lys Gly Phe Pro Thr Ile Leu Ph - #e Tyr Pro Ala Gly Ser                           465  - #               470  - #               475               - - gac cgc acc ccc atc gtg ttc gag ggc ggc ga - #c cgc tcg ctc aag tcc          1491                                                                        Asp Arg Thr Pro Ile Val Phe Glu Gly Gly As - #p Arg Ser Leu Lys Ser                        480      - #           485      - #           490                   - - ctg acc aag ttc atc aag acc aac gcc aag at - #c ccg tac gag ctg ccc          1539                                                                        Leu Thr Lys Phe Ile Lys Thr Asn Ala Lys Il - #e Pro Tyr Glu Leu Pro                    495          - #       500          - #       505                       - - aag aag ggc tcc gac ggc gac gag ggc acc tc - #g gac gac aag gac aag          1587                                                                        Lys Lys Gly Ser Asp Gly Asp Glu Gly Thr Se - #r Asp Asp Lys Asp Lys                510              - #   515              - #   520                           - - ccc gcg tcc gac aag gac gag ctg taa gcggctatc - #t gaactacccc                1634                                                                        Pro Ala Ser Asp Lys Asp Glu Leu                                                525                 5 - #30                                                     - - aggtttggag cgtctgcttg cgcgcttgcg cttgcacact gtgcatggat gg -              #gagttaag   1694                                                                  - - gaggagacgg agcacggagg ctgcgctcgg ttggtggctt ggagcaccgg ca -             #gcgcgtga 1754                                                                    - - tccgtcctgg cagcagcaac ggcggagcgg gcgcatattg gcgcgagctg gc -             #gagcggct   1814                                                                  - - gttgctggag aggatatgct gccgggcggg aggaagggct aggggcagag at -             #gagagcgt 1874                                                                    - - tacgggctgg catgcgggcg cccgtgcctc tccctgcggt gcagtccttg ct -             #aggagacg   1934                                                                  - - cacggttttg ccaaagaggg acgctgtcca cagccctgcg actggaagtt tt -             #ttaggccc   1994                                                                  - - tgcggtggta gtggtgttgg tacggttgtg tgcataagat gaacaacgtt tc -             #tctcaaga   2054                                                                  - - cgagactact agtatgctga cggtgtgtgt atgtggtgga tggattgtgc cc -             #cgaccatg   2114                                                                  - - aagagtgctg tgttgcctcg gcgcttctgt cgccctggat gtgcgtggtt cc -             #gaacgctg   2174                                                                  - - gagtcatctg ttgaggagcg agggtgttgt cgggtccgcc cggcacggcc gc -             #gtgatgtc   2234                                                                  - - cggatgggga ttgcgagcga gggcaaccgc agcgcagata gcgccgcagc gg -             #atcgagct   2294                                                                  - - agcgcaggat gatgagagcc gggccttcgc ggcgtgggat cagggaggag cc -             #aaggcgga   2354                                                                  - - gtgcatgcga ggaaaacagt gtgcggcaaa gaacgggctg caagaacgcc tt -             #gcgcaaa    2413                                                                  - -  - - <210> SEQ ID NO 11                                                   <211> LENGTH: 4                                                                <212> TYPE: PRT                                                                <213> ORGANISM: Chlamydomonas reinhardtii                                       - - <400> SEQUENCE: 11                                                         - - Cys Gly His Cys                                                             1                                                                             - -  - - <210> SEQ ID NO 12                                                   <211> LENGTH: 4                                                                <212> TYPE: PRT                                                                <213> ORGANISM: Chlamydomonas reinhardtii                                       - - <400> SEQUENCE: 12                                                         - - Lys Asp Glu Leu                                                             1                                                                             - -  - - <210> SEQ ID NO 13                                                   <211> LENGTH: 1424                                                             <212> TYPE: DNA                                                                <213> ORGANISM: Chlamydomonas reinhardtii                                      <220> FEATURE:                                                                 <221> NAME/KEY: CDS                                                            <222> LOCATION: (252)..(1310)                                                  <220> FEATURE:                                                                 <221> NAME/KEY: misc.sub.-- feature                                            <222> LOCATION: (279)                                                          <223> OTHER INFORMATION: Codon also can encode - #Ser                          <220> FEATURE:                                                                 <221> NAME/KEY: misc.sub.-- feature                                            <222> LOCATION: (282)                                                          <223> OTHER INFORMATION: Codon also can encode - #Glu                          <220> FEATURE:                                                                 <221> NAME/KEY: misc.sub.-- feature                                            <222> LOCATION: (294)                                                          <223> OTHER INFORMATION: Codon also can encode - #Gly                          <220> FEATURE:                                                                 <221> NAME/KEY: misc.sub.-- feature                                            <222> LOCATION: (306)                                                          <223> OTHER INFORMATION: Codon also can encode - #Asn                          <220> FEATURE:                                                                 <221> NAME/KEY: misc.sub.-- feature                                            <222> LOCATION: (357)                                                          <223> OTHER INFORMATION: Codon also can encode - #Leu                          <220> FEATURE:                                                                 <221> NAME/KEY: misc.sub.-- feature                                            <222> LOCATION: (369)                                                          <223> OTHER INFORMATION: Codon also can encode - #Thr                          <220> FEATURE:                                                                 <221> NAME/KEY: misc.sub.-- feature                                            <222> LOCATION: (486)                                                          <223> OTHER INFORMATION: Codon also can encode - #Ser                          <220> FEATURE:                                                                 <221> NAME/KEY: misc.sub.-- feature                                            <222> LOCATION: (495)                                                          <223> OTHER INFORMATION: Codon also can encode - #Ile                          <220> FEATURE:                                                                 <221> NAME/KEY: misc.sub.-- feature                                            <222> LOCATION: (510)                                                          <223> OTHER INFORMATION: Codon also can encode - #Ala                          <220> FEATURE:                                                                 <221> NAME/KEY: misc.sub.-- feature                                            <222> LOCATION: (555)                                                          <223> OTHER INFORMATION: Codon also can encode - #Val                          <220> FEATURE:                                                                 <221> NAME/KEY: misc.sub.-- feature                                            <222> LOCATION: (588)                                                          <223> OTHER INFORMATION: Codon also can encode - #Glu                          <220> FEATURE:                                                                 <221> NAME/KEY: misc.sub.-- feature                                            <222> LOCATION: (600)                                                          <223> OTHER INFORMATION: Codon also can encode - #Leu                          <220> FEATURE:                                                                 <221> NAME/KEY: misc.sub.-- feature                                            <222> LOCATION: (621)                                                          <223> OTHER INFORMATION: Codon also can encode - #Ala                          <220> FEATURE:                                                                 <221> NAME/KEY: misc.sub.-- feature                                            <222> LOCATION: (714)                                                          <223> OTHER INFORMATION: Codon also can encode - #Thr                          <220> FEATURE:                                                                 <221> NAME/KEY: misc.sub.-- feature                                            <222> LOCATION: (729)                                                          <223> OTHER INFORMATION: Codon also can encode - #Ile                          <220> FEATURE:                                                                 <221> NAME/KEY: misc.sub.-- feature                                            <222> LOCATION: (1092)                                                         <223> OTHER INFORMATION: Codon also can encode - #Val                          <220> FEATURE:                                                                 <221> NAME/KEY: misc.sub.-- feature                                            <222> LOCATION: (1191)                                                         <223> OTHER INFORMATION: Codon also can encode - #Ile                          <220> FEATURE:                                                                 <221> NAME/KEY: misc.sub.-- feature                                            <222> LOCATION: (1284)                                                         <223> OTHER INFORMATION: Codon also can encode - #Ala                          <220> FEATURE:                                                                 <221> NAME/KEY: misc.sub.-- feature                                            <222> LOCATION: (1287)                                                         <223> OTHER INFORMATION: Codon also can encode - #Ile                          <220> FEATURE:                                                                 <221> NAME/KEY: misc.sub.-- feature                                            <222> LOCATION: (1290)                                                         <223> OTHER INFORMATION: Codon also can encode - #Glu                          <220> FEATURE:                                                                 <221> NAME/KEY: misc.sub.-- feature                                            <222> LOCATION: (1293)                                                         <223> OTHER INFORMATION: Codon also can encode - #Ala                          <220> FEATURE:                                                                 <221> NAME/KEY: misc.sub.-- feature                                            <222> LOCATION: (1296)                                                         <223> OTHER INFORMATION: Codon also can encode - #Pro                          <220> FEATURE:                                                                 <221> NAME/KEY: misc.sub.-- feature                                            <222> LOCATION: (1302)                                                         <223> OTHER INFORMATION: Codon also can encode - #Thr                          <220> FEATURE:                                                                 <221> NAME/KEY: misc.sub.-- feature                                            <222> LOCATION: (1308)                                                         <223> OTHER INFORMATION: Codon also can encode - #Gly                           - - <400> SEQUENCE: 13                                                         - - cgtcctattt taatactccg aaggaggcag ttggcaggca actgccactg ac -             #gtcccgta     60                                                                  - - agggtaaggg gacgtccact ggcgtcccgt aaggggaagg ggacgtaggt ac -             #ataaatgt    120                                                                  - - gctaggtaac taacgtttga ttttttgtgg tataatatat gtaccatgct tt -             #taatagaa    180                                                                  - - gcttgaattt ataaattaaa atatttttac aatattttac ggagaaatta aa -             #actttaaa    240                                                                  - - aaaattaaca t atg aca gca att tta gaa cgt cgt - #gaa aat tct agc         cta     290                                                                                   Met Thr Ala - #Ile Leu Glu Arg Arg Glu Asn Ser Ser Leu                          1   - #            5      - #            10                      - - tgg gct cgt ttt tgt gag tgg atc act tca ac - #t gaa aac cgt tta tac           338                                                                        Trp Ala Arg Phe Cys Glu Trp Ile Thr Ser Th - #r Glu Asn Arg Leu Tyr                 15             - #     20             - #     25                           - - atc ggt tgg ttc ggt gta atc atg atc cca tg - #t ctt ctt act gca aca           386                                                                        Ile Gly Trp Phe Gly Val Ile Met Ile Pro Cy - #s Leu Leu Thr Ala Thr             30                 - # 35                 - # 40                 - # 45        - - tca gta ttc atc atc gct ttc atc gct gct cc - #g cca gta gac atc gat           434                                                                        Ser Val Phe Ile Ile Ala Phe Ile Ala Ala Pr - #o Pro Val Asp Ile Asp                             50 - #                 55 - #                 60               - - ggt atc cgt gaa cca gtt tca ggt tct ctt ct - #t tac ggt aac aac atc           482                                                                        Gly Ile Arg Glu Pro Val Ser Gly Ser Leu Le - #u Tyr Gly Asn Asn Ile                         65     - #             70     - #             75                   - - att aca ggt gct gta atc cca act tct aac gc - #a atc ggt ctt cac ttc           530                                                                        Ile Thr Gly Ala Val Ile Pro Thr Ser Asn Al - #a Ile Gly Leu His Phe                     80         - #         85         - #         90                       - - tac cca att tgg gaa gct gct tct cta gac ga - #g tgg tta tac aac ggt           578                                                                        Tyr Pro Ile Trp Glu Ala Ala Ser Leu Asp Gl - #u Trp Leu Tyr Asn Gly                 95             - #    100             - #    105                           - - ggt cct tac caa ctt atc gtt tgt cac ttc ct - #t cta ggt gta tac tgc           626                                                                        Gly Pro Tyr Gln Leu Ile Val Cys His Phe Le - #u Leu Gly Val Tyr Cys            110                 1 - #15                 1 - #20                 1 -       #25                                                                               - - tac atg ggt cgt gag tgg gaa tta tct ttc cg - #t tta ggt atg cgt         cca      674                                                                     Tyr Met Gly Arg Glu Trp Glu Leu Ser Phe Ar - #g Leu Gly Met Arg Pro                           130  - #               135  - #               140               - - tgg atc gct gta gct tac tca gct cca gta gc - #t gca gct tca gct gta           722                                                                        Trp Ile Ala Val Ala Tyr Ser Ala Pro Val Al - #a Ala Ala Ser Ala Val                        145      - #           150      - #           155                   - - ttc tta gtt tac cct atc ggc caa ggt tca tt - #c tct gac ggt atg cct           770                                                                        Phe Leu Val Tyr Pro Ile Gly Gln Gly Ser Ph - #e Ser Asp Gly Met Pro                    160          - #       165          - #       170                       - - tta ggt atc tct ggt act ttc aac ttc atg at - #c gta ttc caa gca gaa           818                                                                        Leu Gly Ile Ser Gly Thr Phe Asn Phe Met Il - #e Val Phe Gln Ala Glu                175              - #   180              - #   185                           - - cac aac atc ctt atg cac cca ttc cac atg tt - #a ggt gtt gct ggt gta           866                                                                        His Asn Ile Leu Met His Pro Phe His Met Le - #u Gly Val Ala Gly Val            190                 1 - #95                 2 - #00                 2 -       #05                                                                               - - ttc ggt ggt tca tta ttc tca gct atg cac gg - #t tct tta gtt act         tca      914                                                                     Phe Gly Gly Ser Leu Phe Ser Ala Met His Gl - #y Ser Leu Val Thr Ser                           210  - #               215  - #               220               - - tct tta atc cgt gaa aca act gaa aac gaa tc - #a gct aac gaa ggt tac           962                                                                        Ser Leu Ile Arg Glu Thr Thr Glu Asn Glu Se - #r Ala Asn Glu Gly Tyr                        225      - #           230      - #           235                   - - cgt ttc ggt caa gaa gaa gaa act tac aac at - #t gta gct gct cat ggt          1010                                                                        Arg Phe Gly Gln Glu Glu Glu Thr Tyr Asn Il - #e Val Ala Ala His Gly                    240          - #       245          - #       250                       - - tac ttt ggt cgt cta atc ttc caa tac gct tc - #t ttc aac aac tct cgt          1058                                                                        Tyr Phe Gly Arg Leu Ile Phe Gln Tyr Ala Se - #r Phe Asn Asn Ser Arg                255              - #   260              - #   265                           - - tca tta cac ttc ttc tta gct gct tgg ccg gt - #a atc ggt att tgg ttc          1106                                                                        Ser Leu His Phe Phe Leu Ala Ala Trp Pro Va - #l Ile Gly Ile Trp Phe            270                 2 - #75                 2 - #80                 2 -       #85                                                                               - - act gct tta ggt tta tca act atg gca ttc aa - #c tta aac ggt ttc         aac     1154                                                                     Thr Ala Leu Gly Leu Ser Thr Met Ala Phe As - #n Leu Asn Gly Phe Asn                           290  - #               295  - #               300               - - ttc aac caa tca gta gta gac tca caa ggt cg - #t gta cta aac act tgg          1202                                                                        Phe Asn Gln Ser Val Val Asp Ser Gln Gly Ar - #g Val Leu Asn Thr Trp                        305      - #           310      - #           315                   - - gca gac atc atc aac cgt gct aac tta ggt at - #g gaa gta atg cac gag          1250                                                                        Ala Asp Ile Ile Asn Arg Ala Asn Leu Gly Me - #t Glu Val Met His Glu                    320          - #       325          - #       330                       - - cgt aac gct cac aac ttc cct cta gac tta gc - #t tca act aac tct agc          1298                                                                        Arg Asn Ala His Asn Phe Pro Leu Asp Leu Al - #a Ser Thr Asn Ser Ser                335              - #   340              - #   345                           - - tca aac aac taa ttttttttta aactaaaata aatctggtta ac - #cataccta              1350                                                                        Ser Asn Asn                                                                    350                                                                             - - gtttatttta gtttatacac acttttcata tatatatact taatagctac ca -              #taggcagt   1410                                                                  - - tggcaggacg tccc              - #                  - #                       - #   1424                                                                   - -  - - <210> SEQ ID NO 14                                                   <211> LENGTH: 1278                                                             <212> TYPE: DNA                                                                <213> ORGANISM: Chlamydomonas reinhardtii                                      <220> FEATURE:                                                                 <221> NAME/KEY: CDS                                                            <222> LOCATION: (1)..(1272)                                                     - - <400> SEQUENCE: 14                                                         - - atg ggc cat cat cat cat cat cat cat cat ca - #t cac agc agc ggc cat            48                                                                        Met Gly His His His His His His His His Hi - #s His Ser Ser Gly His              1               5 - #                 10 - #                 15               - - atc gaa ggt cgt cat atg gcg act act gag tc - #c tcg gcc ccg gcg gcc            96                                                                        Ile Glu Gly Arg His Met Ala Thr Thr Glu Se - #r Ser Ala Pro Ala Ala                         20     - #             25     - #             30                   - - acc acc cag ccg gcc agc acc ccg ctg gcg aa - #c tcg tcg ctg tac gtc           144                                                                        Thr Thr Gln Pro Ala Ser Thr Pro Leu Ala As - #n Ser Ser Leu Tyr Val                     35         - #         40         - #         45                       - - ggt gac ctg gag aag gat gtc acc gag gcc ca - #g ctg ttc gag ctc ttc           192                                                                        Gly Asp Leu Glu Lys Asp Val Thr Glu Ala Gl - #n Leu Phe Glu Leu Phe                 50             - #     55             - #     60                           - - tcc tcg gtt ggc cct gtg gcc tcc att cgc gt - #g tgc cgc gat gcc gtc           240                                                                        Ser Ser Val Gly Pro Val Ala Ser Ile Arg Va - #l Cys Arg Asp Ala Val             65                 - # 70                 - # 75                 - # 80        - - acg cgc cgc tcg ctg ggc tac gcc tac gtc aa - #c tac aac agc gct ctg           288                                                                        Thr Arg Arg Ser Leu Gly Tyr Ala Tyr Val As - #n Tyr Asn Ser Ala Leu                             85 - #                 90 - #                 95               - - gac ccc cag gct gct gac cgc gcc atg gag ac - #c ctg aac tac cat gtc           336                                                                        Asp Pro Gln Ala Ala Asp Arg Ala Met Glu Th - #r Leu Asn Tyr His Val                        100      - #           105      - #           110                   - - gtg aac ggc aag cct atg cgc atc atg tgg tc - #g cac cgc gac cct tcg           384                                                                        Val Asn Gly Lys Pro Met Arg Ile Met Trp Se - #r His Arg Asp Pro Ser                    115          - #       120          - #       125                       - - gcc cgc aag tcg ggc gtc ggc aac atc ttc at - #c aag aac ctg gac aag           432                                                                        Ala Arg Lys Ser Gly Val Gly Asn Ile Phe Il - #e Lys Asn Leu Asp Lys                130              - #   135              - #   140                           - - acc atc gac gcc aag gcc ctg cac gac acc tt - #c tcg gcc ttc ggc aag           480                                                                        Thr Ile Asp Ala Lys Ala Leu His Asp Thr Ph - #e Ser Ala Phe Gly Lys            145                 1 - #50                 1 - #55                 1 -       #60                                                                               - - att ctg tcc tgc aag gtt gcc act gac gcc aa - #c ggc gtg tcg aag         ggc      528                                                                     Ile Leu Ser Cys Lys Val Ala Thr Asp Ala As - #n Gly Val Ser Lys Gly                           165  - #               170  - #               175               - - tac ggc ttc gtg cac ttc gag gac cag gcc gc - #t gcc gat cgc gcc att           576                                                                        Tyr Gly Phe Val His Phe Glu Asp Gln Ala Al - #a Ala Asp Arg Ala Ile                        180      - #           185      - #           190                   - - cag acc gtc aac cag aag aag att gag ggc aa - #g atc gtg tac gtg gcc           624                                                                        Gln Thr Val Asn Gln Lys Lys Ile Glu Gly Ly - #s Ile Val Tyr Val Ala                    195          - #       200          - #       205                       - - ccc ttc cag aag cgc gct gac cgc ccc agg gc - #a agg acg ttg tac acc           672                                                                        Pro Phe Gln Lys Arg Ala Asp Arg Pro Arg Al - #a Arg Thr Leu Tyr Thr                210              - #   215              - #   220                           - - aac gtg ttc gtc aag aac ttg ccg gcc gac at - #c ggc gac gac gag ctg           720                                                                        Asn Val Phe Val Lys Asn Leu Pro Ala Asp Il - #e Gly Asp Asp Glu Leu            225                 2 - #30                 2 - #35                 2 -       #40                                                                               - - ggc aag atg gcc acc gag cac ggc gag atc ac - #c agc gcg gtg gtc         atg      768                                                                     Gly Lys Met Ala Thr Glu His Gly Glu Ile Th - #r Ser Ala Val Val Met                           245  - #               250  - #               255               - - aag gac gac aag ggc ggc agc aag ggc ttc gg - #c ttc atc aac ttc aag           816                                                                        Lys Asp Asp Lys Gly Gly Ser Lys Gly Phe Gl - #y Phe Ile Asn Phe Lys                        260      - #           265      - #           270                   - - gac gcc gag tcg gcg gcc aag tgc gtg gag ta - #c ctg aac gag cgc gag           864                                                                        Asp Ala Glu Ser Ala Ala Lys Cys Val Glu Ty - #r Leu Asn Glu Arg Glu                    275          - #       280          - #       285                       - - atg agc ggc aag acc ctg tac gcc ggc cgc gc - #c cag aag aag acc gag           912                                                                        Met Ser Gly Lys Thr Leu Tyr Ala Gly Arg Al - #a Gln Lys Lys Thr Glu                290              - #   295              - #   300                           - - cgc gag gcg atg ctg cgc cag aag gcc gag ga - #g agc aag cag gag cgt           960                                                                        Arg Glu Ala Met Leu Arg Gln Lys Ala Glu Gl - #u Ser Lys Gln Glu Arg            305                 3 - #10                 3 - #15                 3 -       #20                                                                               - - tac ctg aag tac cag agc atg aac ctg tac gt - #c aag aac ctg tcc         gac     1008                                                                     Tyr Leu Lys Tyr Gln Ser Met Asn Leu Tyr Va - #l Lys Asn Leu Ser Asp                           325  - #               330  - #               335               - - gag gag gtc gac gac gac gcc ctg cgt gag ct - #g ttc gcc aac tct ggc          1056                                                                        Glu Glu Val Asp Asp Asp Ala Leu Arg Glu Le - #u Phe Ala Asn Ser Gly                        340      - #           345      - #           350                   - - acc atc acc tcg tgc aag gtc atg aag gac gg - #c agc ggc aag tcc aag          1104                                                                        Thr Ile Thr Ser Cys Lys Val Met Lys Asp Gl - #y Ser Gly Lys Ser Lys                    355          - #       360          - #       365                       - - ggc ttc ggc ttc gtg tgc ttc acc agc cac ga - #c gag gcc acc cgg ccg          1152                                                                        Gly Phe Gly Phe Val Cys Phe Thr Ser His As - #p Glu Ala Thr Arg Pro                370              - #   375              - #   380                           - - ccc gtg acc gag atg aac ggc aag atg gtc aa - #g ggc aag ccc ctg tac          1200                                                                        Pro Val Thr Glu Met Asn Gly Lys Met Val Ly - #s Gly Lys Pro Leu Tyr            385                 3 - #90                 3 - #95                 4 -       #00                                                                               - - gtg gcc ctg gcg cag cgc aag gac gtg cgc cg - #t gcc acc cag ctg         gag     1248                                                                     Val Ala Leu Ala Gln Arg Lys Asp Val Arg Ar - #g Ala Thr Gln Leu Glu                           405  - #               410  - #               415               - - gcc aac atg cag gcg cgc atg taa ggatcc   - #                  - #              1278                                                                      Ala Asn Met Gln Ala Arg Met                                                                420                                                               __________________________________________________________________________ 

What is claimed is:
 1. An expression cassette for expression of a desired molecule, which cassette comprises:a) an RB47 binding site nucleotide sequence upstream of a restriction endonuclease site for insertion of a desired coding sequence to be expressed; and b) a nucleotide sequence encoding a polypeptide which binds RB47 binding site.
 2. The expression cassette of claim 1 further comprising a promoter sequence operably linked to and positioned upstream of the RB47 binding site nucleotide sequence.
 3. The expression cassette of claim 2 wherein the promoter sequence is derived from a psbA gene.
 4. The expression cassette of claim 3 wherein the coding sequence is heterologous to the psbA gene.
 5. The expression cassette of claim 1 wherein the cassette comprises a plasmid or virus.
 6. The expression cassette of claim 1 further comprising and operably linked thereto a nucleotide sequence encoding RB60.
 7. The expression cassette of claim 1 wherein the RB47 binding polypeptide is selected from the group consisting of RB47, RB47 precursor and a histidine-modified RB47.
 8. An expression cassette for expression of a desired molecule, which cassette comprises:a) an RB47 binding site nucleotide sequence upstream of a restriction endonuclease site for insertion of a desired coding sequence to be expressed;and b) a nucleotide sequence encoding a polypeptide which regulates the binding of RB47 to the RB47 binding site.
 9. The expression cassette of claim 8 wherein the regulatory polypeptide is RB60.
 10. A method of screening for agonists or antagonists of RB47 binding to RB47 binding site, the method comprising the steps:a) providing a cell expression system containing:1) a promoter sequence; 2) a RB47 binding site sequence; 3) a coding sequence for an indicator polypeptide; and 4) a polypeptide which binds to the RB47 binding site sequence; b) introducing an antagonist or agonist into the cell; and c) detecting the amount of indicator polypeptide expressed in the cell.
 11. A method of screening for agonists or antagonists of RB60 in regulating RB47 binding to RB47 binding site, the method comprising the steps:a) providing an expression system in a cell containing:1) a promoter sequence; 2) a RB47 binding site sequence; 3) a coding sequence for an indicator polypeptide; 4) a polypeptide which binds to the RB47 binding site sequence; and 5) a RB60 polypeptide; b) introducing an agonist or antagonist into the cell; and c) detecting the amount of indicator polypeptide expressed in the cell.
 12. An isolated nucleotide sequence encoding RB47.
 13. An isolated nucleotide sequence encoding a histidine-modified RB47.
 14. An isolated nucleotide sequence encoding RB47 precursor.
 15. The nucleotide sequence of claim 12 from nucleotide position 197 to 1402 in FIGS. 1A-1B and SEQ ID NO
 5. 16. The nucleotide sequence of claim 13 from nucleotide position 1 to 1269 in FIGS. 5A-5B and SEQ ID NO
 14. 17. The nucleotide sequence of claim 14 shown in from nucleotide position 197 to 2065 in FIGS. 1A-1C and SEQ ID NO
 5. 18. An expression cassette comprising the nucleotide sequence of claim 12, 13 or
 14. 19. An isolated nucleotide sequence encoding RB60.
 20. The nucleotide sequence of claim 18 from nucleotide position 16 to 1614 in FIGS. 2A-2B and SEQ ID NO
 10. 21. An expression cassette comprising the nucleotide sequence of claim
 19. 22. An expression system comprising a cell transformed with the expression cassette of claim
 1. 23. The expression system of claim 22 wherein the cell is a plant cell.
 24. The expression system of claim 23 wherein the plant cell endogenously expresses RB47.
 25. The expression system of claim 23 wherein the plant cell endogenously expresses RB60.
 26. The expression system of claim 23 wherein the plant cell endogenously expresses RB47 and RB60.
 27. The expression system of claim 22 wherein the cell is a eukaryotic cell.
 28. The expression system of claim 22 wherein the cell is a prokaryotic cell.
 29. The expression system of claim 22 further comprising the expression cassette of claim
 21. 30. An expression system comprising a cell transformed with the expression cassette of claim
 8. 31. The expression system of claim 29 further comprising the expression cassette of claim
 18. 32. A cell stably transformed with the expression cassette of claim
 18. 33. A cell stably transformed with the expression cassette of claim
 21. 34. A cell stably transformed with the expression cassette of claims 18 and
 21. 35. The expression cassette of claim 1 further comprising an inserted desired coding sequence.
 36. An expression system comprising a cell transformed with the expression cassette of claim 35, wherein the coding sequence is expressed forming the desired molecule upon activation of the RB47 binding site with RB47.
 37. The expression system of claim 36 wherein the cell is a plant cell endogenously expressing RB47.
 38. The expression system of claim 36 wherein the cell is stably transformed with the expression cassette of claim
 21. 39. An expression system comprising a cell transformed with an expression cassette comprising a promoter sequence, a RB47 binding site sequence, a desired coding sequence for a molecule, and a nucleotide sequence for encoding a polypeptide which binds RB47 binding site, wherein all sequences are operably linked.
 40. A method of preparing a desired recombinant molecule wherein the method comprises cultivating the expression system of claim
 36. 41. A method of preparing a desired recombinant molecule wherein the method comprises cultivating the expression system of claim
 39. 42. A method for expressing a desired coding sequence comprising:a) forming an expression cassette by operably linking:1) a promoter sequence; 2) a RB47 binding site sequence; 3) a desired coding sequence; and 4) a nucleotide sequence encoding a polypeptide which binds RB47 binding site; and b) introducing the expression cassette into a cell.
 43. The method of claim 42 wherein the cell is a plant cell endogenously expressing RB47.
 44. The method of claim 42 wherein the cell is a plant cell endogenously expressing RB60.
 45. The method of claim 42 further comprising inducing expression with a promoter inducer molecule.
 46. The method of claim 45 wherein the promoter inducer molecule is IPTG.
 47. The method of claim 42 wherein the cell is transformed with the expression cassette of claim
 21. 48. A method for expressing a desired coding sequence comprising:a) forming an expression cassette by operably linking:1) a promoter sequence; 2) a RB47 binding site sequence; and 3) a desired coding sequence;and b) introducing the expression cassette into a plant cell endogenously expressing RB47.
 49. The method of claim 48 wherein the expression cassette further comprises a nucleotide sequence encoding RB60.
 50. A method for the regulated production of a recombinant molecule from a desired coding sequence in a cell, wherein the cell contains the expression cassette of claim 34, wherein expression of the coding sequence is activated by RB47 binding to the RB47 binding site thereby producing the recombinant molecule.
 51. A method of forming an expression cassette by operably linking:a) a RB47 binding site sequence; b) a cloning site for insertion of a desired coding sequence downstream of the RB47 binding site sequence; and c) a nucleotide sequence encoding a polypeptide which binds the RB47 binding site.
 52. The method of claim 51 further comprising a promoter sequence operably linked upstream to the RB47 binding site sequence.
 53. The method of claim 51 further comprising a desired coding sequence inserted into the insertion site.
 54. An article of manufacture comprising a packaging material and contained therein in a separate container the expression cassette of claim 1, wherein the expression cassette is useful for expression of a desired coding sequence, and wherein the packaging material comprises a label which indicates that the expression cassette can be used for expressing a desired coding sequence when the RB47 binding site is activated by RB47.
 55. The article of manufacture of claim 54 further comprising in a separate container the expression cassette of claim
 18. 56. The article of manufacture of claim 54 further comprising in a separate container the expression cassette of claim
 21. 57. An article of manufacture comprising a packaging material and contained therein in a separate container the expression system of claim 22, wherein the expression system is useful for expression of a desired coding sequence, and wherein the packaging material comprises a label which indicates that the expression system can be used for expressing a desired coding sequence when the RB47 binding site is activated by RB47.
 58. An article of manufacture comprising a packaging material and contained therein in a separate container the stably transformed cell of claim 32, wherein the cell is useful as an expression system, and wherein the packaging material comprises a label which indicates that the expression system can be used for expressing a desired coding sequence when the RB47 binding site is activated by RB47.
 59. An article of manufacture comprising a packaging material and contained therein in a separate container the stably transformed cell of claim 33, wherein the cell is useful as an expression system, and wherein the packaging material comprises a label which indicates that the expression system can be used for expressing a desired coding sequence when the RB47 binding site is activated by RB47 and regulated by RB60.
 60. An article of manufacture comprising a packaging material and contained therein in a separate container the stably transformed cell of claim 34, wherein the cell is useful as an expression system, and wherein the packaging material comprises a label which indicates that the expression system can be used for expressing a desired coding sequence when the RB47 binding site is activated by RB47 and regulated by RB60.
 61. An article of manufacture comprising a packaging material and contained therein in a separate container the expression cassette of claim 2, wherein the expression cassette is useful for expression of a RNA transcript, and wherein the packaging material comprises a label which indicates that the expression cassette can be used for producing in vitro a RNA transcript when the RB47 binding site is activated by RB47.
 62. The article of manufacture of claim 61 wherein the promoter sequence is selected from the group consisting of T3 and T7 promoters.
 63. The article of manufacture of claim 61 further comprising in separate containers a polymerase, a buffer and each of four ribonucleotides, reagents for in vitro RNA transcription. 